Дисертації з теми "Migration and Food packaging"

Microwave heating of food has increased rapidly as a food processing technique. This increases the concern that chemicals could migrate from food packaging to food. The specific effect of microwave heating in contrast to conventional heating on overall and specific migration from common plastic food storage boxes was studied in this work. The purpose was especially to determine the interaction effects of different plastics in contact with different types of foods during microwave heating. The study focused on polycarbonate (PC), poly(ethylene terephthalate) (PET), polypropylene homo-polymer (PP), co-polymer (PP-C) and random co-polymer (PP-R) packages. The migration determinations were evaluated at controlled times and temperatures, using a MAE device. The migrants were analyzed by GC-MS and HPLC. ESI-MS was evaluated as a new tool for migration determinations. Food/food simulant absorption and changes in degree of crystallinity during heating were also followed. Significant degradation of antioxidants Irgafos 168 and Irganox 1010 in PP packages occurred during microwave heating of the packages in food simulants containing ethanol, resulting in the formation of antioxidant degradation products. Degradation of PC by Fries chain rearrangement reaction leading to formation of 9,9-dimethylxanthene, and transesterification of PET leading to formation of diethyl terephthalate, were also observed after microwave heating the packages in ethanol and 90/10 isooctane/ethanol. These reactions were not observed during conventional heating of the packages at the same temperature, or after microwave heating of the packages in liquid food (coconut milk). The microwave heating also significantly increased the migration of cyclic oligomers from PET into ethanol and isooctane at 80 °C. Migration of compounds into coconut milk was slightly lower than calculated amounts using the EU mathematical model to predict migration of additives into foodstuffs. The results thus show that the use of ethanol as a fat food simulant during microwave heating can lead to a significant overestimation of migration as well as degradation of polymer or the incorporated additives. Some other detected migrants were dimethylbenzaldehyde, 4-ethoxy-ethyl benzoate, benzophenone, m-tert-butyl phenol and 1-methylnaphthalene. All identified migrants with associated specific migration limit (SML) values migrated in significantly lower amounts than the SML values during 1 h of microwave heating at 80 °C. The antioxidant diffusion coefficients in PP and PP co-polymers showed larger relative differences than the corresponding degrees of crystallinity in the same polymers and PP-R showed by far the fastest migration of antioxidants.
Mikrovågsuppvärmning av mat har ökat markant under de senaste åren. Detta ökar risken för att ämnen i plast migrerar från matförpackningar till mat. Den specifika effekten av mikrovågsvärmning i kontrast till konventionell värmning på total och specifik migrering från vanliga matförvaringslådor av plast studerades i denna avhandling. Syftet var i huvudsak att bestämma interaktionseffekter mellan olika typer av plaster och olika typer av mat under mikrovågsvärmning. Studien fokuserades på förpackningar av polykarbonat (PC), polyetentereftalat (PET), polypropylen homopolymer (PP), copolymer (PP-C) och random copolymer (PP-R). Migreringstesterna utfördes under kontrollerade tider och temperaturer genom att använda MAE. Migranterna analyserades med hjälp av GC-MS och HPLC. ESI-MS-analys utvärderades också som ny analysmetod för migreringstester. Absorption av mat- och matsimulanter samt förändringar i kristallinitetsgrad följdes också. Signifikant nedbrytning av antioxidanterna Irgafos 168 och Irganox 1010 i PP-förpackningar inträffade under mikrovågsvärmning av förpackningarna i etanol-innehållande matsimulanter, vilket resulterade i bildning av nedbrytningsprodukter från antioxidanterna. Nedbrytning av PC genom en Fries omfördelningsreaktion, vilket orsakade bildning av 9,9-dimetylxanten, samt transesterifikation av PET, vilket orsakade bildning av dietyltereftalat, observerades också efter mikrovågsvärmning av förpackningarna i etanol och 90/10 isooktan/etanol. Dessa reaktioner observerades ej efter konventionell värmning av förpackningarna under samma temperatur och ej heller efter mikrovågsvärmning av förpackningarna i riktig mat (kokosmjölk). Mikrovågsvärmningen ökade också betydelsefullt migrering av cykliska oligomerer från PET till etanol och isooktan under 80 °C. Specifika ämnens migrering till kokosmjölk var alla något lägre än migreringsvärden beräknade m. h. a. EU's officiella matematiska modell för förutsägelse av migrering från matförpackningar till mat. Dessa resultat visar att användandet av etanol som matsimulant för fet mat under mikrovågsvärmning kan leda till betydande överestimering av migrering, samt nedbrytning av polymer och additiv i polymeren. Andra detekterade migranter var till exempel dimetylbenzaldehyd, 4-etoxy-etylbenzoat, benzofenon, m-tertbutylfenol och 1-metylnaftalen. Alla identifierade migranter med tillhörande ‘specific migration limit’ (SML)-värden migrerade i betydelsefullt mindre mängder än ämnenas tillhörande SML-värden under 1 h mikrovågsvärmning under 80°C. Diffusionskoefficienterna för antioxidanterna i PP-förpackningarna visade större relativa skillnader än förpackningarnas motsvarande kristallinitetsgrader och migrering av antioxidanter var snabbast från PP-R.

QC 20120530

Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Chemistry in the Faculty of Applied Sciences at the Cape Peninsula University of Technology
Paperboard made from recycled fibres is being used more frequently in direct food packaging applications, in addition to its use as secondary and tertiary packaging. However, recent research has shown that there is a risk that harmful chemicals may migrate from the paperboard into the food. The simplest approach to reducing the migration of these contaminants is the use of barrier films. The barrier efficiencies of these various films can be examined by means of a migration test into a food simulant, followed by extraction in a suitable solvent. The extract can then be analysed by chromatographic techniques such as gas chromatography mass spectrometry (GC-MS) to determine the concentration of the specific contaminants. However on a production level, the availability of this type of highly specialised equipment is limited. A simple, cost effective method is needed to evaluate the barrier properties to specific chemical contaminants. The Heptane Vapour Transmission Rate (HVTR) test is a permeation test method for use at quality control level to determine barrier properties to the migration of organic vapours. The first part of the study focussed on establishing a universal correlation between HVTR and specific migration of diisobutyl phthalate (DiBP), dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP) that would be applicable to any type of functional barrier. However, experimental data demonstrated this was not possible as the correlation factor linking HVTR to specific migration was largely dependent on the type and morphology of the coating considered. The initial objective of the study was reconsidered in favour of building individual models specific to the nature of the coating and substrate considered. A correlation between HVTR and specific migration of DiBP, DBP and DEHP for a polyvinylidene chloride (PVDC) barrier polymer was constructed by varying the applied coating weight. The vapour transport mechanism for the HVTR test and the specific migration test were found to differ, showing that a direct correlation between HVTR and the specific migration was again not possible. However, an indirect correlation could be made. The HVTR method gives an indication of film integrity, whereas the coating weight could be used as an indicator of the specific migration. The correlation between the coating weight and the specific migration yielded an equation that can be used to calculate the specific migration through the PVDC barrier polymer, provided the quantity of the chemical contaminant originally present in the paperboard was known. This equation was specific to the type of barrier polymer, the specific chemical contaminant as well as the intended shelf-life of the food product to be packaged in the paperboard.

Thesis (MSc)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The presence of mineral oils in dry foodstuff was found to originate from the packaging materials, namely, paperboard manufactured from recovered fibres, and these oils subsequently migrate to the foodstuff via the vapour phase. The presence of mineral oils in food is of concern as it originates from the use of paper products not originally intended for food contact applications, i.e., before the paper is subjected to a suitable recycling process. These mineral oils consist of technical grade compounds which may contain aromatic compounds and other components with unknown toxicological effects. Although the related authorities are currently considering the safe and legal limits of these contaminants in foodstuffs, as well as establishing a standardised test method for monitoring mineral oils in food and packaging materials, paperboard manufacturers wish to ensure that their products are safe for food contact applications. Since recycling is unavoidable, particularly from an ecological and economical point of view, one of the proposed solutions the industry is focussing on is the use of a functional barrier towards mineral oils – be it an inner bag as a direct food-contact surface, or a barrier coating directly applied on the inner side of the paperboard. In this study, a permeation test method was established, and developed, to evaluate the transmission rate of a volatile organic compound, acting as a mineral oil simulant, through model paper and plastic packaging materials. This was correlated to the transmission rate of actual mineral oil through the packaging materials, and therefore used as a highly accelerated tool to characterise packaging materials in relation to their barrier properties. The test method, referred to as the “heptane vapour transmission rate,” was subsequently used to derive the required transport parameters’ characteristics of each of the tested materials, which enabled an evaluation of the potential shelf-life of the packaged product. This research demonstrated that barrier-coated paperboards have the ability to behave in the same way as, and often even better than, commercial plastic films, towards the migration of mineral oil. Detailed information on the interaction between the packaging materials and mineral oil simulant, n-heptane, was acquired from gravimetric sorption. Insight was obtained into a material’s ability to function as a mineral oil barrier. It was established that the quick and easy permeation method was sufficient for evaluating packaging materials as potential mineral oil barriers, and resulted in the determination of transport parameters that were higher than that obtained by sorption. The obtained transport parameters could therefore be considered a worst case scenario when predicting the package content shelf-life.
AFRIKAANSE OPSOMMING: Daar is voorheen bevind dat die teenwoordigheid van mineraalolies in droë voedsel afkomstig is van die verpakkingsmateriaal, naamlik karton, wat vervaardig is van herwonne papierprodukte, en daarna migreer die olies na die voedsel deur die gasfase. Die teenwoordigheid van hierdie mineraalolies in kos wek groot kommer aangesien dit afkomstig is van papierprodukte wat nie oorspronklik bedoel is vir voedselkontak voor die herwinningsproses nie. Die olies bestaan uit industriële graad mineraalolies wat moontlik aromatiese verbindings asook ander komponente bevat waarvan die toksiekologiese effekte onbekend is. Terwyl die betrokke owerhede tans besig is om die veilige en wettige grense van hierdie kontaminante in voedsel te oorweeg, asook die vestigting van 'n gestandaardiseerde toetsmetode vir die kontrole van mineraalolies in die voedsel-verpakkingsmateriaal-kombinasie, wil karton- en papiervervaardigers graag verseker dat hul produkte veilig is vir voedselkontak. Siende dat herwinning onvermydelik is vanuit 'n ekologiese en ekonomiese oogpunt, is een van die voorgestelde oplossings in die bedryf om te fokus op die gebruik van 'n funksionele keerfilm ten opsigte van mineraalolies, wat ‘n sakkie binne-in die karton, wat dien as die direkte kos-kontakoppervlak, of 'n keerlaag, wat direk aangewend word op die binnekant van die karton, kan behels. Hierdie studie ondersoek die daarstel en deursypelingsontwikkeling van 'n toetsmetode om die oordragtempo van 'n vlugtige organiese verbinding, wat optree as 'n mineraalolie simulant, deur middel van model papier- en plastiekverpakkingsmateriale, te evalueer. Dit stem ooreen met die oordragtempo van werklike mineraalolies deur die verpakkingsmateriaal en kan dus gebruik word as 'n hoogs versnelde instrument om verpakkingsmateriale te karakteriseer met betrekking tot hul keereienskappe. Die toetsmetode, die sogenaamde "heptaangasoordragtempo," is vervolgens gebruik om die vereiste oordragparameters af te lei wat kenmerkend is van elk van die geëvalueerde verpakkingsmateriale en wat sodoende gebruik kon word om die potensiële raklewe van die verpakte produk te bepaal. Hierdie navorsing het getoon dat kartonprodukte met ‘n keerlaag die vermoë het om dieselfde op te tree as kommersiële plastiekfilms en dikwels selfs beter, ten opsigte van die migrasie van mineraalolies. Gedetailleerde inligting oor die interaksie tussen die verpakkingsmateriale en mineraalolie simulant, n-heptaan, is verkry vanaf gravimetriese sorpsie. Dit gee insig in 'n materiaal se vermoë om te funksioneer as 'n mineraalolie-keermiddel. Daar is vasgestel dat die vinnige en maklike deurwerking metode voldoende is vir die evaluering van verpakkingsmateriale as potensiële mineraalolie-keermiddels, en verleen oordragparameters wat hoër is as dié verkry deur sorpsie. Hierdie oordragparameters kan dus as 'n ergste scenario vir die voorspelling van die raklewe van ‘n verpakte produk beskou word.

A major problem associated with the development of complex polymeric materials for food contact applications is the potential for migration of toxic substances from the polymer to the food. This thesis investigates the transfer of migrants from non-ovenable food contact materials at elevated temperatures, and several applications where migration has occurred have been identified. Boil in the bag applications lead to exposure times of 30 - 120 minutes for complex multilayer laminates, whilst plastic kettles are repeat exposure items, and plastic 'vacuum flasks' have a potential for up to 4 hours exposure. Analytical techniques including, GC-MS, LC-MS, HPLC and UV spectroscopy have been employed to quantify the species migrating from these food contact materials into aqueous and oil simulants, and to ensure that they conform to the implemented EC restrictions. Olive oil is a stipulated EC fatty food simulant, but it is unsuitable for specific migration analyses since it contains many interfering compounds. These could not be eliminated by repeated solvent extraction, and a silicone oil was therefore substituted. In an attempt to identify the species migrating into aqueous and fatty food simulants both the final materials and also the individual components i.e. nylon, adhesive, polyethylene and polypropylene were examined separately. HPLC techniques have been developed to quantify both the known levels of antioxidants present in the polymers and also the anticipated degradation products from these materials. Typical levels of antioxidants in simulants range from <0.1 (aqueous) to 45j..lgdm-2 (oil) and <0.1 (aqueous) to 200j..lgdm" (oil) for antioxidant degradation products. In commercial boil in the bag laminates the major migrants have been shown to be derived principally from the nylon film, and the polyurethane adhesive used to fabricate the laminate. Le-MS investigations have confirmed the presence of the residual monomer Ecaprolactarn and its cyclic oligomers (up to the nonarner) in aqueous food simulants boiled in direct contact with the nylon 6. This technique has also identified the main migrants from the aliphatic and aromatic polyurethane adhesives to be residual oligomers from the polyols. Any residual isocyanates in the adhesive are converted to the corresponding amine, and colourimetric assays have determined levels between 1.1 and O.lj..lgdm". Measured, migration levels into fatty food simulants were found to be greater than in aqueous food simulants. However, none of the material examined showed an overall migration value greater than the EC limit of 10mg dm" for single sided testing. Some instances were found where the consumer was instructed to boil the dry food part of a boil in the bag meal in the same water as that used to heat the pouch containing the meat, and under these circumstances a total migration value for the laminate greater than 10mg dm-2 was measured.

Migrazione di sostanze organiche attraverso rivestimenti bio-polimerici da imballaggi in carta e cartone per uso alimentare Obiettivi perseguiti durante il presente dottorato di ricerca sono stati: l’ottenimento di dati sulla migrazione dei contaminanti tipicamente presenti in imballaggi di carta e cartone negli alimenti e la valutazione dell'efficacia di bio-polimeri deposti su carta come materiali barriera. Nella prima parte del progetto, è stata eseguita un’indagine analitica di materiali cartacei per uso alimentare allo scopo di identificare le sostanze chimiche più comuni con un potenziale di trasferimento verso gli alimenti. Tali materiali sono stati selezionati in considerazione di una vasta gamma di utilizzi (dal confezionamento primario e secondario agli articoli per fast food). È stato condotto uno screening analitico mediante tecniche di micro estrazione in fase solida (SPME) ed estrazione con solvente (SE) entrambe seguite da successiva analisi mediante gascromatografia-spettrometria di massa (GC-MS) al fine di determinare le principali molecole volatili e semi-volatili in essi presenti. Un gran numero di analiti sono stati rilevati, conseguentemente, per analizzare tali dati, è stato utilizzato un approccio di tipo chemiometrico. Attraverso l’analisi delle componenti principali (PCA) sono stati identificati e selezionati alcuni composti come marker per la classificazione dei campioni. Il metodo analitico utilizzato, combinato con l’approccio chemiometrico, si è dimostrato essere efficace per la trattazione di tali dati. In seguito è stata eseguita una ricerca documentale dedicata a proprietà tossicologiche o restrizioni legislative delle sostanze individuate. La semi-quantificazione dei composti negli imballaggi, ha consentito, mediante l’applicazione del modello di migrazione totale a tempo infinito, una stima della contaminazione di alimenti in condizioni limite; occasionalmente, tali stime portano al superamento dei limiti di migrazione previsti dalla legge. In aggiunta, è stato condotto uno studio sulla presenza di di-isobutile ftalato (DiBP) in film di polivinil cloruruo (PVC) destinato al contatto alimentare. Si è dimostrato come l’origine della contaminazione di tale imballaggio plastico primario per alimenti, fosse costituita dall’imballaggio secondario in cartone (astucci e mandrini in fibra riciclata) utilizzato per la distribuzione e lo stoccaggio di tali tipologie di materiali. Nella seconda parte della ricerca, sono stati sviluppati e caratterizzati rivestimenti a base di biopolimeri applicati su substrati di carta. In particolare, sono stati considerati rivestimenti a base acquosa, costituititi da biopolimeri rinnovabili, tra i quali: amidi modificati (waxy e ad alto contenuto di amilosio), proteine animali (glutine e gelatina). La caratterizzazione dei campioni di carta bio-rivestita è stata condotta mediante misure di angolo di contatto e osservazioni microstrutturali. Allo stesso tempo, sono stati realizzati studi di ripartizione e diffusione di molecole selezionate tra carta o carta bio-rivestita e aria o simulanti alimentari, inoltre; quale confronto, sono stati considerati diversi rivestimenti plastici. Notevoli differenze sono state evidenziate nell’adsorbimento dei contaminanti tra carta bio-rivestita o non rivestita e aria. I minori coefficienti di ripartizione sono stati raggiunti nella carta bio-rivestita, rendendo evidente come i biopolimeri testati siano stati capaci di ridurre l’affinità del substrato carta nei confronti di tali contaminanti. Tali risultati sono stati discussi in relazione delle caratteristiche proprie di ogni biopolimero. Studi di diffusione nel simulante alimentare solido poli 2,6-difenil-p-fenilene ossido, noto anche come Tenax®, hanno confermato che tutti i biopolimeri testati rallentano la migrazione. I dati sperimentali sono stati interpretati mediante modello di Weibull. L’ultima parte dell’attività di ricerca è stata dedicata alla migrazione di composti similari agli oli minerali ed alla valutazione dell’efficacia di rivestimenti a base amido su carta come materiali barriera. La cinetica di migrazione di composti modello (n-alcani: C10-C40) in Tenax® è stata studiata sia mediante HPLC-GC-FID che un sistema di misurazione della permeazione in continuo. L’applicazione di modelli attualmente disponibili ha permesso il confronto con i dati misurati sperimentalmente. Infine, sono stati condotti test di migrazione utilizzando materiali realmente contaminati da oli minerali.
This PhD thesis is aimed to generate data on migration of typical contaminants from Paper and Board (P&B) packaging into food and on the effectiveness of bio-based polymers coated onto paper as barrier materials. In the first part of the project, an analytical survey of P&B materials intended for food use was carried out with the aim to identify chemicals with a potential to migrate into foods. A screening was applied by means of Solid Phase Micro Extraction (SPME) and solvent extraction (SE) with subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS) to determine volatile and non-volatile molecules. A large number of analytes were detected and a chemometric approach was used to explore the data. PCA (Principal Component Analysis) was used to identify and select some compounds as markers for sample classification. The chosen analytical method coupled with chemometrics proved to be an effective way in processing these data. A literature survey for safety data or legislative restrictions of the identified substances was performed. The semi-quantification of the compounds in the packaging allowed a worst case estimation of food contamination by means of the infinite total migration model; occasionally, migration estimations overcame the specific migration limits. Additionally, a study to investigate the occurrence of diisobutyl phthalate (DiBP) in polyvinyl chloride (PVC) cling films for food contact applications was carried out. It demonstrated the contamination pathway from the secondary paper packaging (contaminated materials, such as folding cardboards and inner cores made of recycled fibres) used for distribution and storage of these primary plastic packaging that will be in contact with food. In the second part of the project, coatings of different biopolymers onto paper substrates were developed and characterized. Focus was directed to water-based, renewable biopolymers, such as: modified starches (cationic starch and cationic waxy starch), plant and animal proteins (gluten and gelatine), poured onto paper with an automatic applicator. Optical contact angle measurements and microstructural observations of the bio-coated paper allowed the characterization of the samples. At the same time, partition and diffusion studies of selected substances of toxicological concern were carried out between paper/coated paper and air or food simulants, additionally, a comparison with a polyethylene laminated paper was performed. The aim was to evaluate the physicochemical behaviour and the barrier properties of bio-coatings against migration of typical contaminants from recycled paper packaging. From the partitioning studies, considerable differences in the adsorption behaviour of the selected contaminants between bio-coated or uncoated paper and air were highlighted. Lowest values of partition coefficients were achieved when paper was bio-coated, making evident that biopolymers reduced the affinity of the paper substrate for the tested migrants. These findings were discussed considering the characteristics of the tested biopolymers. Diffusion studies into the solid food simulant poly 2,6-diphenyl-p-phenylene oxide, also known as Tenax®, confirmed that all the tested biopolymers slowed down migration. The Weibull kinetic model was fit to the experimental data to compare migration from paper and bio-coated paper. Finally, research activity was focused on the migration of contaminants like MOSH (mineral oil saturated hydrocarbons) and on the evaluation of starch based bio-coatings as barrier materials. Migration test series were performed up to 10 days at 60 °C using spiked model substances (n-alkanes C10-C40) and Tenax® as food simulant. HPLC-GC-FID system was used to analyse extracts and its relative performances were compared with an automatic permeation system. Existing predictive models for migration were preliminary applied for comparison with measured data. Finally, migration test series with real contaminated packaging materials were developed.

Food packaging protects food, but it can sometimes become a source of undesired contaminants. Paper based materials, despite being perceived as “natural” and safe, can contain volatile contaminants (especially if made from recycled paper) able to migrate to food, as mineral oil, phthalates and photoinitiators. Mineral oil is a petroleum product used as printing ink solvent for newspapers, magazines and packaging. From paperboard printing and from recycled fibers (if present), mineral oil migrates into food, even if dry, through the gas phase. Its toxicity is not fully evaluated, but a temporary Acceptable Daily Intake (ADI) of 0.6 mg kg-1 has been established for saturated mineral oil hydrocarbons (MOSH), while aromatic hydrocarbons (MOAH) are more toxic. Extraction and analysis of MOSH and MOAH is difficult due to the thousands of molecules present. Extraction methods for packaging and food have been optimized, then applied for a “shopping trolley survey” on over 100 Italian and Swiss market products. Instrumental analyses were performed with online LC-GC/FID. Average concentration of MOSH in paperboards was 626 mg kg-1. Many had the potential of contaminating foods exceeding temporary ADI tens of times. A long term migration study was then designed to better understand migration kinetics. Egg pasta and müesli were chosen as representative (high surface/weight ratio). They were stored at different temperatures (4, 20, 30, 40 and 60°C) and conditions (free, shelved or boxed packs) for 1 year. MOSH and MOAH kinetic curves show that migration is a fast process, mostly influenced by temperature: in egg pasta (food in direct contact with paperboard), half of MOSH is transferred to food in a week at 40°C and in 8 months at 20°C. The internal plastic bag present in müesli slowed down the startup of migration, creating a “lag time” in the curves.

Food packaging protects food, but it can sometimes become a source of undesired contaminants. Paper based materials, despite being perceived as “natural” and safe, can contain volatile contaminants (especially if made from recycled paper) able to migrate to food, as mineral oil, phthalates and photoinitiators. Mineral oil is a petroleum product used as printing ink solvent for newspapers, magazines and packaging. From paperboard printing and from recycled fibers (if present), mineral oil migrates into food, even if dry, through the gas phase. Its toxicity is not fully evaluated, but a temporary Acceptable Daily Intake (ADI) of 0.6 mg kg-1 has been established for saturated mineral oil hydrocarbons (MOSH), while aromatic hydrocarbons (MOAH) are more toxic. Extraction and analysis of MOSH and MOAH is difficult due to the thousands of molecules present. Extraction methods for packaging and food have been optimized, then applied for a “shopping trolley survey” on over 100 Italian and Swiss market products. Instrumental analyses were performed with online LC-GC/FID. Average concentration of MOSH in paperboards was 626 mg kg-1. Many had the potential of contaminating foods exceeding temporary ADI tens of times. A long term migration study was then designed to better understand migration kinetics. Egg pasta and müesli were chosen as representative (high surface/weight ratio). They were stored at different temperatures (4, 20, 30, 40 and 60°C) and conditions (free, shelved or boxed packs) for 1 year. MOSH and MOAH kinetic curves show that migration is a fast process, mostly influenced by temperature: in egg pasta (food in direct contact with paperboard), half of MOSH is transferred to food in a week at 40°C and in 8 months at 20°C. The internal plastic bag present in müesli slowed down the startup of migration, creating a “lag time” in the curves.

La maîtrise des interactions aliment/emballage est essentielle pour assurer la sécurité et la qualité des produits emballés. Dans le cadre du Projet Européen Novel Q, nous avons évalué l'impact des traitements de hautes pressions thermales (HP/T) sur les interactions aliment emballage. En particulier, nous avons étudié l'effet d'une pasteurisation (800 MPa, 5 min, 40°C) et une stérilisation (800 MPa, 5 min, 115°C) haute pression sur la migration et le scalping du polyéthylène linéaire de basse densité (LLDPE), du polylactate (PLA) et d'un nanocomposite biodégradable à base de gluten de blé/montmorillonite (WG/MMT). Pour LLDPE et PLA, la caractérisation de la migration s'est basée dans le suivi de deux additifs modèles, Uvitex OB et Irganox 1076 alors que pour le WG/MMT d'autres tests additionnels ont été faits, i. E. Migration globale, des protéines et de nanoparticules. Les traitements HP/T n'ont pas eu un effet significatif sur la plupart d'interactions étudiées sauf pour la migration de nanoparticules du WG et lors du scalping à haute température. Jusqu'à présent, les méthodes le plus fréquemment utilisées pour la détermination de niveaux de migration sont basées dans la destruction et quantification de l'échantillon, s'avérant de méthodes longues et coûteuses. Pour s'affranchir de telles méthodes, la modélisation a été récemment acceptée en tant que méthode d'estimation de migration. Néanmoins, les paramètres nécessaires, c'est-à-dire, la diffusivité et le coefficient de partage ne sont que rarement connus. L'utilisation de la spectroscopie Raman et FTIR pour déterminer des niveaux de migration et surtout, pour estimer la diffusivité d'un additif dans du LLDPE s'est accomplie avec succès, permettant une caractérisation complète du transfert de matière dans le système
The control of food/packaging interactions is essential to ensure the safety and quality of packed products. In particular, in the framework of the European Project Novel Q (IP6, Novel Processing Methods for the Production and Distribution of High Quality and Safe Foods), the effect of high pressure thermal (HP/T) treatments on food/packaging interactions was assessed in a variety of cases. Migration and scalping were studied for linear low density polyethylene (LLDPE), polylactide (PLA) and a wheat gluten/montmorillonite (WG/MMT) nanocomposite novel biodegradable and nanocomposite materials in food simulating liquids (FSL). Food/packaging interactions were studied after two HP/T treatments intended to perform a pasteurization (800 MPa, 5 min, 40°C) and a sterilization (800 MPa, 5 min, 115°C) treatment, as well as subsequent storage for 10 days. Specific migration of an additive (Uvitex OB) was assessed for LLDPE and PLA, whereas additional tests were carried out for WG/MMT, i. E. Overall migration, protein migration and nanoparticles migration. HP/T treatments did not significantly modify the migration or scalping in the conditions studied except for the release of nanoparticles from WG. Interestingly, the increase in the melting point of LLDPE during HP/T made possible to sterilize it. To date the most frequently used methods in migration assessment are based in time consuming methods based on destruction and quantification. To avoid them, modeling has been recently approved as a method for migration assessment. However, the parameters needed, i. E. Diffusivity (D) and the partition coefficient (K) are seldom available. The use of FTIR and Raman spectroscopy to assess migration behavior and, more importantly, to determine the diffusivity of an additive in LLDPE was successfully carried out allowing a complete characterization of mass transfer

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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP

In this thesis, the studies of the 3-year doctoral thesis carried out at the PhD School in Food Systems of the University of Milan between 2018-2021 are presented. The thesis consists of 6 main chapters and each chapter is presented in the form of an article. The main purpose of the project was to investigate the safety of cellulose nanocrystals (CNCs) in detail when used as a food contact material, and to contribute to their safety assessments to take advantage of their use to increase the functionalities of packaging films without using petroleum-based plastic materials. First, a review (Chapter 1) was written to get better insight into what the engineered nanomaterials (ENMs) are and what the detection methods are to test them better. After a broad literature review, CNCs were taken as a specific case of ENMs and all the techniques for their characterization and the pros and cons of this material were discussed. A roadmap about the CNCs characterization was created based on recent guidelines published by EFSA. Then, CNCs were evaluated in-depth to define their physicochemical characteristics and morphological feature in Chapter 2 to be used as reference material for further studies. Additionally, the suspicion of the existence of CNCs in some products that are prone to human consumption sheds light on our work on this subject. Even if CNCs are not intentionally added to the food products we consume, they may have the potential to enter our bodies through the consumption of certain food products. For this reason, different kinds of microcrystalline cellulose (MCC) sources were chosen to represent a sort of approved cellulosic additive source. Due to their similar production ways which generally consist of a chemical acidic hydrolysis, possibly followed by ultrasonication, it was reasonable to search for the presence of CNCs in different MCCs. If the existence of CNC can be proven in MCC, safety concerns must change the direction. For this purpose, different sources of MCCs have been investigated to trace the possible presence of CNCs in Chapters 3 and 4 to support EFSA requirements for the safety of nanoparticles in the food chain. After the comprehensive characterization and detection of CNCs in different food additive sources, they were integrated into polymeric matrices in two different ways: as coating on polyethylene terephthalate (PET) films and as a reinforcement material in polylactic acid (PLA). Investigations to observe the migration and/or release of nano-sized matter from these polymeric combinations were done. Since the risk assessment of CNCs, in this case, requires new methodologies for their physicochemical characterization, a combination of advanced techniques that differ from traditional analytical techniques was used to study the migration. Therefore, in Chapters 5 and 6, the characteristics of the reference CNCs defined in previous chapters were used to investigate and define the nano-sized matter released/migrated from the polymeric matrices to the food simulants after the incubation period.

Les emballages plastique sont tristement connus pour la pollution accrue qu’ils entrainent. Les effets directs sur l’homme sont principalement dus à la migration de composés depuis le plastique vers les aliments qu’il contient. Ces composés ont des origines diverses : additifs, impuretés, produits de dégradations, réactions non contrôlées… A défaut de savoir arrêter cette migration, nous avons choisi d’en tirer profit grâce à de nouveaux matériaux, appelés matériaux actifs. Ces derniers ont pour objectifs de prolonger la durée de vie des aliments grâce à une migration dite « positive ». L’utilisation d’additifs naturels pose cependant un problème lié à leur résistance à la température. La problématique est donc de trouver des additifs naturels résistant à la température de mise en œuvre des polymères, tout en les stabilisant. C’est dans ce contexte que mon sujet de thèse a été mis en place, au sein du projet Foodyplast (POCTEFA). La thèse se découpe en quatre parties. Un état de l’art est tout d’abord présenté. Le chapitre suivant détaille les différentes techniques utilisées pour la réalisation et la caractérisation de nos matériaux ainsi que le développement d’une nouvelle méthode basée sur la spectrométrie de masse (LESA-MS). Le troisième chapitre aborde en détail la mise en œuvre de nouveaux matériaux stabilisés par des additifs naturels ainsi que leurs caractérisations physico-chimiques. Nous avons prouvé que l’utilisation conjointe de ces additifs (alpha-tocopherol/acide ascorbique et alpha-tocopherol/tannins) permet d’accroitre significativement l’effet de stabilisation sur la matrice polymère (innovation brevetée). Ces matériaux ont également montré être recyclable jusqu’à 9 fois sans dégradations. Enfin, le dernier chapitre reprend la nouvelle méthode du LESAMS, développée au chapitre 2, pour l’appliquer à la caractérisation de nos matériaux. Cette méthode est comparée à celle de la norme européenne en vigueur et ouvre de réelles perspectives d’analyses performantes dans les polymères pour différentes applications
Plastic packagings are notorious for the increased pollution they cause. The direct effects on humans are mainly due to the migration of compounds from plastic to the foods it contains. These compounds have various origins: additives, impurities, degradation products, uncontrolled reactions… For lack of being able to stop this migration, we chose to take advantage of it with new materials, called active materials. The objectives of these materials are to extend the shelf life of foods through a so-called “positive” migration. However, the use of natural additives is complicated due to their poor resistance to temperature. The problem is therefore to find natural additives resistant to the polymers’ extrusion temperatures, while stabilizing them. It is in this context that my thesis topic was set up within the Foodyplast project (POCTEFA). The thesis is divided into four parts. A state of the art is first presented. The following chapter details the various techniques used to produce and characterize our materials and the development of a new method based on mass spectrometry (LESA-MS). The third chapter discusses in detail the implementation of new materials stabilized by natural additives and their physico-chemical characterization. We have shown that the joint use of these additives (alpha tocopherol/ascorbic acid and alpha-tocopherol/tannins) significantly increases the stabilization effect on the polymer matrix (patented innovation). These materials have also shown to be recyclable up to 9 times without degradation. Finally, the last chapter potential of the new LESA-MS method (developed in Chapter 2) for its efficient of our materials. This method is compared to that of the current European standard and opens up real prospects for performing analyses in polymers for different applications

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Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energéticas e Nucleares - IPEN/CNEN-SP

Les emballages alimentaires existent depuis la nuit des temps, depuis que l'homme transporte des aliments solides ou liquides. Comme tous les matériaux destinés à entrer au contact des aliments, le bois peut être une source de contaminations chimiques et/ou biologiques, il est donc soumis au règlement (CE) 1935/2004 du parlement européen. Cependant en France, la réglementation spécifique « bois » date de novembre 1945. Elle définit les espèces autorisées pour le contact alimentaire. Il existe également une note d'information « bois » de l'agence sanitaires française « DGCCRF » qui détaillent quelques phénomènes de migration entre le bois et l'aliment mais elles sont très peu développées. L'objectif de cette thèse est d'étudier les différents facteurs qui influencent la migration des composés organiques du bois après un contact alimentaire afin de développer une méthodologie d'analyse simple applicable par les industriels de l'emballage. A l'échelle locale, ce projet innovant apporte une réponse auprès des autorités sanitaires françaises et auprès de la filière française emballages bois et palettes. Et fournira des éléments nécessaires pour la mise à jour de la fiche « matériau bois n°2012-93 » et permettront aux industries agroalimentaires d'avoir à disposition une méthode d'analyse de référence
Food packaging has existed for millennia; ever since man wished to transport solid or liquid foods that were gathered previously. As in the case most materials, wood could be a source of contamination by chemical or biological products. To date, there are no studies available that assess the migration potential of wood components in to food. Food in contact with materials, like wood, is subject to the European Regulation (EC) 1935/2004. In contrast to other materials, there is no specific directive for wooden food contact packaging. In France, the only specific regulation concerning "wood" dates from November 1945 and is very underdeveloped. This thesis aims to study various factors that influence the migration of organic compounds from wood to food when in direct or indirect contact with one another. The final outcome will be a simple methodology that can be applied to industrial packaging. At the national level, this innovative project is in response to the needs of both the French health authorities and the French wood packaging industry. And provide the information necessary to update the information contained in "wood material No. 2012-93” which will, in turn, give the food industry an analytical method and a point of reference

Neben der Sicherheit für Lebensmittel stehen auch immer mehr die Lebensmittelverpackungen im Fokus der Öffentlichkeit. Der Übergang von Stoffen aus der Verpackung in das Lebensmittel ist unerwünscht und gesetzlich reglementiert. Um den Verbraucherschutz zu gewährleisten, müssen Grenzwerte und gesetzliche Anforderungen eingehalten werden. Der Übergang von rechtlich geregelten und nicht geregelten Substanzen muss überprüft werden, was eine analytische Herausforderung darstellt. Die Untersuchung der migrierenden stickstoffhaltigen Substanzen aus Doseninnenbeschichtungen mittels eines Screenings aller migrierenden nicht-flüchtigen stickstoffhaltigen Substanzen mit einer molaren Masse kleiner 1000 Da wurde durchgeführt. Die Anwendbarkeit eines Stickstoff-selektiven Detektors für das Screening von Coating-Extrakten, welche stickstoffhaltige Verbindungen enthalten konnte gezeigt werden. Gegenstand der Untersuchung waren Vernetzersubstanzen, Flüssiglacke sowie Migrate der fertigen Beschichtung. Stickstoffhaltige potenziell migrierende Substanzen wurden zunächst in den Ausgangsmaterialien der Beschichtung identifiziert, um diese dann im Migrat der Beschichtung zu quantifizieren. Es sollte gezeigt werden, ob Substanzen, welche als Ausgangsstoffe im Lack eingesetzt werden, oder entstehende Reaktionsprodukte in ein Lebensmittelsimulanz migrieren. Um die Relevanz der migrierenden stickstoffhaltigen Verbindungen im Hinblick auf weitere nicht stickstoffhaltige migrierende Verbindungen zu zeigen, wurde das Gesamtmigrat der zur Verfügung stehenden Coatings bestimmt. Es zeigte sich, dass der Anteil von NCS an den insgesamt migrierenden Verbindungen zwischen 0,2 und 6,3 % liegt. Der Fokus des zweiten Teils der vorliegenden Arbeit liegt auf Lebensmittelverpackungen aus Kunststoff. Zunächst wurde eine HPLC-Methode mit Hilfe des Verdampfungslichtstreudetektors zur Bestimmung der Gesamtmigration mit dem Simulanz Sonnenblumenöl etabliert werden. Das Ziel dieser Untersuchungen ist, den Einfluss von Temperatur, Zeit und Schichtdicke auf das Migrationsverhalten von Siegelschichten für den Hochtemperaturbereich (> 70 °C) mit fetthaltigen Lebensmitteln mit Hilfe von statistischer Versuchsplanung vorherzusagen. Mit Hilfe einer statistischen Software konnte eine Regressionsgleichung zur Berechnung der Gesamtmigration auf der Grundlage eines Box-Behnken-Versuchsplans erstellt werden. Dabei hatte die Temperatur den größten Einfluss auf die Gesamtmigration. Die Einflüsse von Zeit und Schichtdicke waren im untersuchten Bereich des hier gezeigten Modells linear und stiegen mit Erhöhung der Temperatur. Weiterhin konnte je 10 °C Temperaturerhöhung eine Verdopplung des ermittelten Gesamtmigrationswertes beobachtet werden. Die Bestimmung der Additive aus den Ersatzsimulanzien 95 % Ethanol und Iso-Octan von Verpackungen sollte ebenfalls gezeigt werden. Ein Screening-Gradient zur Bestimmung von 25 Additiven in den Ersatzsimulanzien wurde etabliert. Die Identifizierung der migrierenden Additive erfolgte mittels der Detektoren UVD (DAD), FLD, ELSD und CLND. Mit Hilfe der verschiedenen Detektionsarten ist es möglich, die strukturelle Vielfalt der eingesetzten Additive abzudecken. Eine Absicherung der Ergebnisse konnte zudem über MS-Detektion erfolgen. Mit Hilfe der Untersuchungen wurden die gesamtmigrierenden Substanzen aus Verbundfolien zu 50 % (95 % Ethanol-Migrat) bzw. 10 % (Isooctan-Migrat) aufgeklärt. Die Konzentration der quantifizierten Additive zeigte im Verhältnis gesehen annähernd gleiche Werte. Der Unterschied in den ermittelten Gesamtmigraten (95 % Ethanol: 1,2 mg/dm2, Iso-Octan: 5,6 mg/dm2) konnte demnach nicht über die migrierenden Additive erklärt werden. Als weitere migrierende Substanzen wurden Ethylen-Oligomere identifiziert. Die Quantifizierung dieser erfolgte erstmals mit Hilfe der 1H-NMR-Spektroskopie. Die nahezu vollständige Aufklärung der Gesamtmigration einer Verbundfolie in den Ersatzsimulanzien konnte gezeigt werden. Die migrierenden Ethylen-Oligomere des Iso-Octan-Migrats wurden eingehender untersucht. Mit Hilfe von verschiedenen chromatographischen und spektroskopischen Methoden gelang eine Charakterisierung dieser im Migrat identifizierten Substanzen
Besides the safety of food the focus on food packaging material increases in public. The migration of substances from the packaging into food is undesired and regulated by law. To ensure consumer protection legal limits and requirements have to be kept. The migration of regulated und not regulated substances has to be verified which means an analytical challenge. The determination of nitrogen containing substances (NCS) from food can coatings by screening of migrating, non-volatile substances with a molecular mass below 1000 Da from the coatings was carried out. The applicability of a nitrogen selective detector for the screening of coating extracts which contain nitrogen containing susbtances was shown. For the investigations crosslinking substances, liquid lacquers as well as migrates of the finished coatings have been available for determination. Nitrogen containing and potential migrating substances have been identified first in the raw marterial of the coating in order to quantify them in the migrates of the coating. It should be shown if substances from the raw materials or reaction products migrate into the food simulant. In order to show the relevance of the migrating nitrogen containing substances in respect to other non nitrogen containing compounds the overall migration of the available coatings was determined. It could be shown that the amount of NCS in the overall migrating substances was between 0.2 and 6.3 %. Focus of the second part of the work was on food packing made of plastic. First an HPLC-method with ELS detection for the determination of the overall migration in sunflower oil was developed. Purpose of this determination was to predict the influence of temperature, time and thickness of the layer on the migration behavior with fatty food of sealing layers in high temperature range (> 70 °C) by means of design of experiments. A statistical software computed a regression equation for the calculation the overall migration based on a Box-Behnken-Design. The highest influence could be shown for the temperature. The modell showed a duplication of the determined overall migration with 10 °C increase of temperature. The determination of plastic additives out of the 95 % ethanol and isooctane migrates of packaging material should also be conducted. An HPLC-screening method for the determination of 25 additives in the fat substitutes was established. The identification of the migrating additives was carried out with UV detection (DAD), FLD, ELSD and CLND. By means of the different detection systems it was possible to cover the structural diversity of the mainly used additives. To insure the results MS detection was used. By means of this investigations a clarification of the total migrating substances of a multilayer film was 50 % (95 % ethanol) and 10 % (isooctane), respectively. The concentration of the migrating substances on the scale of things is nearly identical. The difference in the overall migration (95 % ethanol: 1.2 mg/dm2, isooctane: 5.6 mg/dm2) can not be clarified by migration of additives. As other migrating substances ethylen oligomers can be identified. The quantification was carried out for the first time with 1H﷓NMR spectroscopy. An almost complete identification of migration substances of the overall migrate in food simulants can be shown. The migrating ethylen oligomers have been further investitgated. With the help of different chromatographic and spectroscopic methods a further characterisation of the migrating ethylen oligomers was successul

La contamination des aliments peut résulter de diverses interactions entre les aliments emballés et les matériaux d'emballage, notamment de la migration de faibles quantités de composés constituants ces matériaux. Elle est importante des points de vue économique et sanitaire. Cette étude consiste en identification de composés volatils du bois de peuplier et en la détermination de leur diffusivité dans des aliments modèles et des aliments réels. Les modèles mathématiques développés pour prédire le taux de migration des composés volatils, à partir du peuplier vers des aliments de géométries différentes, ont permis d'estimer la concentration des composés migrant dans l'aliment emballé. Différents systèmes d'emballage ont été simulés pour le dosage expérimental de composés migrant dans le produit emballé. L’ensemble des résultats expérimentaux confirme la validité des modèles et des algorithmes de calcul proposés dans cette étude.

Packaging has been on the environmental agenda for decades. It has been discussed and debated within the society mainly as an environmental problem. Production, distribution and consumption of food and drinks contribute significant to the environmental impact. However, consumers in the EU waste about 20% of the food they buy. The function of packaging in reducing the amount of food losses is an important but often neglected environmental issue. This thesis focuses on the functions of packaging that can be used to preserve resources efficiently and reduce the environmental impact of the food-packaging system. The service perspective is used to increase knowledge about consumer interaction with packages. Fifteen packaging attributes, for example, ‘easy to empty’, ‘hygienic’ and ‘contain the right quantity’, were identified as influencing the amount of food losses at the consumer. The result showed that there are potentials to both increase consumer satisfaction and decrease the environmental impact of the food-packaging system, when new packaging design reduces food losses. A model was developed that calculates the balance of environmental impact between reduction of food losses, and more packaging material. The result showed that it can be environmentally motivated to increase the environmental impact of packaging, if the amount of food losses is reduced. This is especially true for food items with high environmental impact, e.g. meat and dairy products, and for food items that have a high share of loss, e.g. bread. I have also explored to what extent packaging can influence food losses in households. The study showed that about 20% to 25% of household food waste was related to packaging. The households noted three packaging attributes as the main causes for food losses; ‘too big packaging’, ‘difficult to empty’ and ‘best-before-date’. Finally there is a discussion of packaging research in the context of sustainability principles, and suggestions for further research.

Paper IV was still a manuscript at the time of the thesis defense.

The global amount of waste generated by households, including food packaging waste, has been increasing continuously across the world, posing a massive threat to societies and the environment. Proper waste management, therefore, has become a challenging environmental issue and a priority for governments. Along with the technological advances, such as material recovery technologies, more stress has been placed on the strategies for moving away from disposal to waste prevention, separation, and recycling. Considerable efforts are being made to not only limit the overall production and the negative impact of waste on the environment and human health but also to minimize the cost of waste management. Separation of wastes at the source (i.e., source separation) is an integral part of such efforts toward enhancing the purity of collected waste and improving the quality of materials for recycling. Furthermore, sorting of waste as a habitual performance can serve as a practice for improving residents' recycling/sorting behavior. The packaging waste, including food packaging, forms a significant part of the municipal solid waste. The design of food packaging, therefore, has received a lot of attention as a useful tool to influence the consumers' sorting behavior, making it an interesting concept for research related to waste management. Presumably, the design of food packaging can meet consumers' sorting demands while being instructive and facilitating the sorting process, thus enhancing the recycling rate of the food packaging waste. Finding the ideal form of food packaging, however, requires an in-depth understanding of the packaging-consumer interactions throughout the sorting process. Considering the different characteristics of food packaging, it is expected that different food packages tend to influence a consumer in different ways. Nevertheless, the current knowledge is somewhat too general to be used by packaging developers to improve the sorting of the food packaging. Hence, the present thesis aims to provide a more in-depth insight into the influence of food packaging, as a product and service provider, on the consumer's/user's decision-making on sort of food packaging waste. The results assert that packaging to be sorted properly requires proper design to manifest its sorting related abilities such as easy to empty, easy to clean, and easy to fold, for the consumer. Selecting material, visual attributes, form, and function can amplify or reduce these sorting abilities of food packaging.

This research centres on product package design related to older people's emotional needs. In particular, knowledge concerning the design of packages for transgenerational use linked to background social data has been elicited. The most distinctive accomplishment has been an exploration of the visual appeal of packaging design in relation to age, gender, education and emotional preference of older consumers. Findings are primarily related to the interaction older people in the UK with selected aspects of package design. Three areas of research have been brought together in this thesis: packaging design and multiple choice, emotional/psychological preference for packaging design characteristics and colour appeal associated ..w ith food character in packaging design. Investigations into the 'third age' and classifications beyond utilised a large sample from the 'Thousand Elders' and a range of packaging designs for selected food items. The significant findings indicate that familiarity and emotional response to packaging designs are key determinants in older consumers' intentions to purchase. Design relating to overall perception or technical cognition are shown to correlate with age related emotional feelings of arousal. Specific findings on such correlations are described in detail. A further 'emotional appeal' was found with colour; for example, green, yellow or bright tones were the most popular colour hue and value associated with varied qualities for food packaging design for specific age groups. Differences between ages, gender and education levels (hypothesised variables linked to design choices) are also analysed and correlated; for example, gender and age rather than educational level combinations appeared to significantly influence choice. Males aged between 55 and 64 relied on their experience of functional aspects for packaging design when considering a purchase. Females in the older age group of 65-74 were more emotional and considered visual appeal in a more personal way. However, few distinguishable psychological effects were noted for the over 75 year olds in their relationship with design. Personal characteristics of older people and their choice are presented in a combination of qualitative interpretation and numeric analysis. Key findings relate to the specific nature of older consumers behaviour in their engagement with packaging design.

Le projet de thèse NanoTi-Food vise principalement à améliorer la fiabilité de la caractérisation des nanoparticules de TiO2 (NPs) et à acquérir des connaissances sur l'additif alimentaire E171 y compris la migration de ces NP à partir des emballages alimentaires. Dans la première partie de l'étude (à réaliser à Anses), une nouvelle approche pour la caractérisation des NP de TiO2 sera développée et optimisée en utilisant l'approche « single particle » en combinaison avec la spectrométrie de masse à plasma à couplage inductif triple quadripôle (Sp-ICP- QQQMS). À cette fin, les paramètres analytiques les plus critiques, tels que les méthodes de calcul de l'efficacité du transport (TE) et le système d'introduction des échantillons seront évalués dans différentes conditions de travail (par exemple gaz de réaction, choix de l'isotope). Dans ce dernier cas, deux systèmes d'introduction d'échantillons à haut rendement (type APEX) seront comparés. Par ailleurs, une approche Sp complémentaire basée sur la MS-ICP haute résolution (Sp-ICP-HR MS) sera développée au LNE. La nouveauté dans ce cas sera l'utilisation d'un ICP-MS à haute résolution (champ de secteur magnétique) pour la détection, qui est la technique de pointe pour la détermination des éléments traces métalliques fortement interférés tels que le Ti. Un système d'injection interne sera également optimisé pour augmenter l'efficacité et la sensibilité du transport de l'échantillon. La validation de la méthode sera réalisée par comparaison inter-laboratoires entre le LNE et l'Anses. Une véritable valeur ajoutée du projet sera l'évaluation de l'incertitude de mesure liée à la caractérisation des NP de TiO2 par les deux approches Sp-ICP-MS (QQQ et HR). Les calculs d'incertitude prendront en compte non seulement la reproductibilité expérimentale et les incertitudes de chacune des variables nécessaires pour convertir le signal ICP-MS en taille et concentration de NPs, mais aussi et pour la première fois, l'effet du choix du seuil pour discriminer le signal ionique ICP-MS de celui des NP. L'effet des écarts par rapport à la forme sphérique sur les tailles sera également étudié et comparé à la microscopie électronique à balayage (MEB), qui est la méthode de référence pour la caractérisation des NP. Le projet vise également la préparation et la caractérisation exhaustive d'un matériau de référence réel (additif alimentaire) contenant des nanoparticules de TiO2. Une étude de faisabilité du développement d'une MR à base de E171 sous forme de suspension sera réalisée. À cette fin, un échantillon E171 représentatif sera préparé et entièrement caractérisé par un panel de techniques complémentaires, telles que SEM, Sp-ICP-QQQMS, Sp-ICP-HR MS, diffraction des rayons X (XRD) pour évaluer avec précision les principaux paramètres d'intérêt, tels que le diamètre médian et moyen, la distribution de taille, la fraction de nanoparticules, les impuretés chimiques et la fraction cristallographique. Enfin, les deux approches analytiques développées à l'Anses et au LNE, dont la méthode développée pour l'évaluation de l'incertitude globale, seront appliquées à l'étude du transfert des NP de TiO2 à partir des emballages alimentaires. Tout au long du projet, les données de taille obtenues en utilisant les nouvelles approches basées sur l'approche « single particle » pour la caractérisation des NP de TiO2 seront comparées aux mesures SEM, qui est la méthode de référence pour la taille dans ce domaine d'étude. Les études sur la migration des emballages alimentaires sont en effet une étude de cas sélectionnée où la Sp-ICP-MS a le potentiel de fournir des informations supplémentaires par rapport à d'autres paramètres tels que la concentration de particules, la proportion de particules par rapport à la forme dissoute, qui sont également importantes pour la migration qui est important afin d'améliorer les études d'évaluation des risques
This PhD project aims primarily to improve the reliability of the characterisation of TiO2 nanoparticles (NPs) and to gain knowledge of the food additive E171 and in real-life applications such as migration of these NPs from food packaging. In the first part of the study (to be carried out at Anses), a new approach for TiO2 NPs characterisation will be developed and optimized by using the single particle approach in combination with inductively coupled plasma-triple quadrupole mass spectrometry (Sp-ICP-QQQMS). For this purpose, the most critical analytical parameters, such as the transport efficiency (TE) calculation methods and the sample introduction system will be assessed under different working conditions (e.g. reaction gas, choice of isotope). In the latter case, two high efficiency sample introduction systems (APEX type) will be critically compared. Further, a complementary Sp approach based on ICP-high resolution MS (Sp-ICP-HRMS) will be developed at LNE. The novelty in this case will be the use of a high resolution (magnetic sector field) ICP-MS for detection, which is the state-of-the art technique for trace and ultra-trace metals determination of highly interfered elements such as the case of Ti. An in-house injection system will also be optimized to increase the transport efficiency and sensitivity. Method validation by inter-laboratory comparison between LNE and ANSES will be achieved here. A truly added value of the project will be the assessment of the measurement uncertainty related to TiO2 NPs characterization by both Sp-ICP-MS (QQQ and HR) approaches. The uncertainty calculations will take into account, not only the experimental reproducibility and the uncertainties of each variables required to convert ICP-MS signal into NPs size and concentration, but also and for the first time, the effect of the choice of the cut-off to discriminate the ICP-MS ionic signal from that of NPs. The effect of deviations from the spherical shape on the sizes will also be explored and compared with scanning electron microscopy (SEM), which is the reference method for NPs characterisation. The project also aims at the preparation and exhaustive characterization of a real-life (food additive) reference material containing TiO2 nanoparticles. A feasibility study of the development of an E171-based RM under a suspension form will be carried out. For this purpose, a representative E171 sample will be prepared and fully characterized by a panel of complementary techniques, such as SEM, Sp-ICP-QQQ MS, Sp-ICP-HRMS, X-ray diffraction (XRD) to accurately assess the main parameters of interest, such as the median and mean diameter, size distribution, fraction of nanoparticles, chemical impurities and crystallographic fraction. Finally, both analytical approaches developed at Anses and LNE, including the developed method for global uncertainty assessment, will be applied to the study of the transfer of TiO2 NPs from food packaging. All along the project, the size data obtained by using the newly developed “single particle” based approaches for TiO2 NPs characterisation will be compared to SEM measurements, which is the reference method for size in this study field. Food packaging migration studies is indeed a selected case study where Sp-ICP-MS has the potential of supplying additional information compared to other instruments, such as: particle concentration, proportion of particulate vs. dissolved form, which are of importance for migration as well as to improve risk assessment studies

Packaging is an integral part of food and goods. Packaging provides safety products that comply with sanitary and aesthetic requirements, standards, ease of use and sales and promotes the competitiveness of products, protects the rights of producers and consumers in the market.

Mestrado em Biotecnologia
A produção de plásticos, baseados no uso de combustíveis fósseis, está a aumentar e estima-se que esta tendência continuará no futuro com impactos ambientais consideráveis. Os bioplásticos são uma alternativa amiga do ambiente. Biopolímeros como quitosana já foram adotados com sucesso para produzir bioplásticos que agem como substitutos do plástico em embalagem. A quitosana foi selecionada devido às suas numerosas vantagens para embalagem alimentar, principalmente devido às suas atividades antioxidantes e antimicrobiana. Por outro lado, o dióxido de titânio foi selecionado como aditivo devido à sua capacidade de retirar oxigénio do ambiente e devido à possibilidade de poder ser facilmente funcionalizado para a formação de um sensor. Isto permitiria a formação de uma embalagem ativa e inteligente na proteção do alimento. Assim, nanopartículas homogéneas arredondadas e monofásicas de anatase de dióxido de titânio (TiO2) foram usadas para melhorar os filmes de quitosana, criando um bionanocompósito. Estas nanopartículas de TiO2 foram produzidas por síntese hidrotermal, tendo sido otimizadas as condições de síntese, como a temperatura e tempo, para selecionar as condições que originam as nanopartículas com as caraterísticas desejadas. As condições escolhidas para a produção do TiO2 foram 200 ºC e 2,5 h devido ao tamanho, dispersão e tipo de nanoparticulas de TiO2 produzidas. Os filmes de quitosana foram preparados com cerca de 9 mg de nanopartículas de TiO2. Para criar uma embalagem ativa e inteligente compostos fenólicos (principalmente antocianinas) de arroz preto (Oryza sativa L. Indica) foram adicionados para funcionalizar o TiO2 (4,1 mg de extrato por filme). Os filmes foram caracterizados em relação à sua atividade antioxidante, humidade, solubilidade, hidrofobicidade da superfície e propriedades mecânicas. Os melhores resultados foram obtidos nos filmes com nanopartículas e compostos fenólicos e foi demonstrado que a forma como cada componente é adicionado altera as suas propriedades. Os melhores resultados foram o aumento da atividade antioxidante, diminuição da solubilidade e da elasticidade, elongação e resistência à tração no filme composto por pigmento e TiO2,. No entanto nestes últimos três parâmetros, a sua diminuição pode ser um aspeto positivo ou negativo dependendo das propriedades desejadas para o filme e o produto alimentar a embalar
Plastic production based in fossil fuels is rising, and predictions supports it continuous and enhanced use, with consequent environmental damage. Bioplastics are an environmentally friendly alternative. Biopolymers as chitosan have already been successfully used to produce bioplastics that act as plastic substitutes in packaging. Chitosan was chosen for its numerous advantages for food packaging namely due to its antioxidant and antimicrobial activities. On the other hand, TiO2 was selected due to its oxygen scavenging ability and due to its possibility to be easily functionalised to create a sensor. This would allow the construction of an active and intelligent packaging for food protection. Thus, monophasic anatase homogeneous round-shaped nanoparticles of titanium dioxide (TiO2) were used as filler to improve the chitosan films, creating a bionanocomposite. These TiO2 nanoparticles were produced via a hydrothermal method and its synthesis was optimized testing various reaction times and temperatures to find the conditions that create TiO2 nanoparticles with the desired features. The conditions used for the chosen TiO2 were 200 ºC and 2.5 h due to the size, dispersion and TiO2 of the nanoparticles produced. The chitosan films were prepared with about 9 mg of TiO2 nanoparticles. To develop an active and intelligent food packaging, phenolic compounds (mainly anthocyanins) from black rice (Oryza sativa L. Indica) were used to functionalise the TiO2 (4.1 mg of extract in each film). The films were characterised regarding its antioxidant activity, humidity, solubility, surface hydrophilicity and mechanical properties. The best results were from films with both nanoparticles and phenolic compounds, and it was established that the order in which they are added alters its properties. The more notable improvements are an increase in antioxidant activity and a decrease in solubility, elasticity, elongation and tensile strength in the film containing pigment and TiO2. However, the reduction of the later three properties can either be positive or negative, it depends on desired properties for the film for a chosen food product

The Food and Agriculture Organization of the United Nations estimates that one-third of food produced (1.3 billion tons annually) is lost or wasted along the food supply chain despite being still fit for human consumption. At the consumer level, misunderstanding of how expiry dates relate to food quality or safety is one of the main reasons leading to unnecessary food waste and also presenting food safety risks. The use-by date is solely used as a guide to indicate peak quality, and in many cases products may be safely consumed past their use-by date. Conversely, for products that have not passed their use-by date, food mishandling such as temperature abuse conditions or contamination can lead to foodborne illnesses. Therefore, an effective indicator for spoilage could eliminate consumer confusion and reduce food waste. In light of this, the present study aims to develop different sensors that can detect meat spoilage at low temperatures, as well as detect the presence of ethylene, which has applications in the monitoring of fruit ripening. During the spoilage of high-protein foods such as meat and fish, several gases, especially ammonia, are released due to the decomposition activity of bacteria. The presence of ammonia in a food package can thus imply that the food has been spoiled. In this study, 10,12-Pentacosadiynoic acid (PCDA) monomers were used as sensing material to detect the presence of ammonia. To render the sensor more practical, chitosan and cellulose nanocrystals (CNC) were used to form a flexible film, like a sticker. By fabricating PCDA/CNC/chitosan composite, the sensor was able to detect ammonia gas at low temperatures, such as in fridge (4 degrees Celsius) and freezer (–20 degrees Celsius) temperatures. By fabricating a PCDA/CNC/chitosan composite, the sensor could successfully detect ammonia gas at low temperatures. The sensor could also detect the spoilage of meat samples that were stored in fridge and freezer temperatures. For some climacteric fruits (e.g., avocado and kiwi), the ripe and unripe stages are barely discernible. People usually check the firmness of a fruit to determine its real-time ripening stage, which generally corresponds to the rate of ripening. To this end, colorimetric sensors are particularly useful. In this study, PCDA was functionalised with the Lawesson reagent, which replaced carboxylic headgroups with the thiol (-SH) headgroups of the PCDA. Chitosan and CNCs were used for the same purposes as the sensor that was developed for detecting ammonia. The newly developed PDA–SH/PDA/CNC/chitosan composite could detect the presence of ethylene through the Michael addition reaction. The sensor’s sensing capacity can be extended so that it is applicable in different environments that require the detection of ethylene. With the same detection aim, PCDA can be further functionalized with N-heterocyclic ligands such as 2,2′-Dipyridylamine (DP). DP can form complexes with Cu+, which has great affinity with ethylene. Due to ethylene–Cu+ binding, the Cu+/PDA- DP/PDA sensing solution changed colour from blue to red when exposed to ethylene. The sensor exhibited high specificity towards ethylene rather than the common interfering gases including carbon dioxide and nitrogen. These results can imply that a sensing material can be diversely functionalised for the same sensing purpose. The sensor capacity can be further extended by incorporating different polymers, such as the two studies mentioned above. Overall, the developed sensing platforms demonstrated great sensitivity and specificity to food quality and safety markers such as ethylene and ammonia. The multi-sensing platforms provide different sensing options and could be further functionally extended for use in different sensing applications.

La cellulosa è il polimero naturale più abbondante sulla terra, una risorsa rinnovabile che ogni anno viene prodotta in miliardi di tonnellate da molti organismi vegetali. Per questa ragione, su di essa si sta concentrando una crescente attenzione nell’ipotesi di una sua sempre maggiore applicazione nei più diversi campi. Quello del food packaging, che è ancora fortemente dipendente da materiali di sintesi e provenienti da risorse non rinnovabili, è particolarmente interessato ad un suo più ampio impiego, anche con il fine di aumentare la sostenibilità dei suoi prodotti e di ridurne l’impatto ambientale. Con questa tesi di dottorato si è inteso mettere a fuoco le potenzialità di impiego della nano cellulosa (cellulose nanocrystals, CNs), sperimentare la produzione e valutare le proprietà di alcune lacche a base di CNs, destinate a ricoprire convenzionali materiali flessibili per il confezionamento alimentare. La tesi si compone di quattro parti distinte. Nella prima parte si è inteso rappresentare lo stato dell’arte delle conoscenze e delle applicazioni della nanocellulosa, attraverso un ampio lavoro di documentazione bibliografica. Dapprima si è voluto mettere a fuoco quanto noto sulla struttura e la classificazione delle varie forme di nanocellulosa che è oggi possibile produrre e, a proposito della cellulosa nanocristallina in particolare, si è fatto il punto sulle tecniche di preparazione, la morfologia e le principali applicazioni. Da questo lavoro di documentazione sono emerse le notevoli proprietà di barriera ai gas ed a potenziali migranti, le eccellenti proprietà meccaniche (resistenza alla rottura, massima elongazione tensile, modulo di Young) e le interessanti caratteristiche termiche (transizione vetrosa, punto di fusione e di decomposizione) della CNs da sola ed in combinazione con altri materiali. Nella seconda sezione della tesi, al fine di comprendere meglio la struttura e la morfologia dei nanocristalli di cellulosa ottenuti attraverso un processo di idrolisi acida di linter di cotone, sono state utilizzate diverse tecniche analitiche avanzate, sia per la caratterizzazione qualitativa che quantitativa. E’ stato così possibile ottenere informazioni precise sulle dimensioni dei nano cristalli, il rapporto di forma, la solubilità e numerose altre loro importanti proprietà. In particolare le tecniche di TEM, SEM, e AFM sono apparse come le più adatte per osservare la morfologia dei cristalli, studiare le caratteristiche e la rugosità delle superfici trattate con lacche a base di CNs. Si è inoltre indagato sulla distribuzione delle dimensioni dei cristalli ottenuti e, grazie all’uso di FTIR, XPS e NMR, sulla natura dei gruppi funzionali disponibili e sulle loro interazioni. La terza parte della tesi è dedicata ad uno studio delle proprietà di alcuni differenti film, largamente impiegati per il food packaging (PET, OPP, OPA e cellophane), rivestiti con uno strato sottile di CNs. In particolare, è statomesso a punto il processo di laccatura e sono state misurate le proprietà ottiche (la trasparenza, l’opacità e le proprietà anti-fog), il coefficiente di frizione statico e dinamico, le energie superficiali e gli angoli di contatto, le proprietà di barriera all’ossigeno ed al vapor d’acqua. Da questo lavoro è emerso come sia effettivamente possibile rivestire di uno strato sottile (intorno ad un micron di spessore), omogeneo e continuo, film plastici differenti e che attraverso questo processo di laccatura, si riduce significativamente il coefficiente di frizione, si incrementano le proprietà anti-fog, si aumenta decisamente la barriera all’ossigeno, senza pregiudicare la trasparenza dei film di supporto. La prospettiva molto concreta è quella di costituire, in un modestissimo spessore, un coating multifunzionale con spiccate caratteristiche di sostenibilità e di sicurezza alimentare. L’ultima sezione della tesi è dedicata al lavoro fatto per sperimentare la possibile applicazione di una tecnica di rivestimento molto moderna (layer-by-layer coating, LbL) che sfrutta la formazione di legami elettrostatici tra biopolimeri caricati diversamente. In particolare si è dimostrata la possibilità di costituire lacche di un composito ottenuto mediante la sovrapposizione alternata di sottilissimi strati (da 6 a circa 30 nm) di chitosano e cellulosa nanocristallina. Il diverso pH delle soluzioni in cui vengono dispersi i due biopolimeri determina un diverso grado di ionizzazione delle cariche, rispettivamente positive del chitosano e negative della cellulosa, e di conseguenza diversi spessori e proporzioni relative dei due biopolimeri nel coating composito che si realizza. Ciò, evidentemente, permette di modulare in un ampio intervallo di valori, la permeabilità del film ricoperto. Il coefficiente di permeabilità del composito giunge a valori pari 0.02 cm3 µm m-2 24h-1 kPa-1, molto simili a quelli espressi da copolimeri a base di EVOH, in condizioni anidre. I vantaggi di un simile rivestimento sono comunque fondamentalmente legati alla sicurezza e non tossicità dei biopolimeri impiegati, dalla loro sostenibilità e dall’ampio grado di libertà disponibile nel modulare le caratteristiche finali di barriera, secondo le esigenze del prodotto da confezionare. Lo strato di lacca LbL così costituita rappresenta, in definitiva, una barriera all’ossigeno particolarmente promettente negli impieghi reali più critici anche per la concreta possibilità di realizzarla convenientemente su oggetti tridimensionali come bottiglie, vassoi e altri imballaggi finiti. In conclusione, le ricerche condotte rappresentano una base di partenza molto promettente per un’innovazione di sostenibilità e di prestazioni nel campo dell’imballaggio flessibile e meritano ulteriori approfondimenti ed applicazioni.
Being cellulose the most abundant natural polymer in biosphere, more and more attention has been paid on its new functionalities, sustainability, and renewability. Meanwhile, food packaging materials is one of the largest products we are using in daily life, but most of conventional materials are still oil-based due to their low cost and good performances. Therefore, in order to improve the sustainability and renewability of food packaging materials, this PhD dissertation focuses on development new nano-material (cellulose nanocrystals, CNs) for food packaging and includes mainly four sections. In the first section of this PhD dissertation, we reviewed the progress in knowledge on nano-cellulose first and then, specifically, on CNs. In this section the structure and classifications of various nano-cellulose preparations are included, as well as the preparation, the morphologies, and applications of CNs. In CNs applications, we reviewed that it exhibits excellent barrier, mechanical, and thermal properties itself or combined with other polymers. Particularly, the barrier properties refer to oxygen, water vapor, and migration barrier; mechanical properties are related with tensile strength, Young’s modulus, and strain percentage; the thermal properties include glass transition and melting or decomposition temperature, heat flow, and thermal mechanical parameters. In the second section of this PhD dissertation, to better understand the structure and status of CNs itself or in other polymers, we have used different powerful analytical tools for qualification and quantification. Firstly, we have obtained the relatively precise dimensions of CNs and observe its redispersability in different solvents, mainly water solutions. In the following, we could gain the information of the CNs status in other polymers in order to interpret the final performance efficiently. Finally, we preliminarily concluded that TEM, SEM, and AFM are suitable tools for observing individual crystals, estimating the roughness, and learning the morphology in different scale, respectively. As for the size distribution, functional groups, and interactions between the atoms of CNs, the particle size distributor, FTIR, XPS, and NMR are used for determinations, respectively. In the third section of this PhD dissertation, we have systematically investigated the properties of conventional films coated with CNs. In particular, we have analyzed their optical properties (transparency and haze), mechanical properties (static and dynamic coefficient of friction), anti-fog (contact angle and surface energy) and barrier properties (oxygen and water vapor transmission rates). In doing this, we have demonstrated that CNs coatings mainly lead to a reduction of friction, a premium feature for industrial applications, and that their influence on the optical properties of the packaging is not significant. Excellent anti-fog property guarantees customers more conveniently to evaluate the product inside the packages easily. At last but not the least, CNs coatings dramatically improve not only the oxygen barrier properties of conventional flexible food packaging, but also lead to a certain reduction in the water vapor transmission rate. The perspective use of CNs as multi-functional coatings favors a reduction of the required thickness for plastic films, towards a more environmentally-friendly and sustainable approach to packaging. In the last section of this PhD dissertation, we demonstrated the use of chitosan (CS)/CNs nanocomposites realized by layer-by-layer (LbL) self-assembly as oxygen barrier under different pH combinations. The oxygen permeability coefficient of CS/CNs nanocomposites is as low as 0.02 cm3 µm m-2 24h-1 kPa-1, close to EVOH co-polymers, under dry conditions. Meanwhile, we consider that CNs has no potential risks for human beings and the renewable origin of the carbohydrate polymers as significant added values that justify a deeper investigation. Finally, it deserves to be underlined also the chance of finely tuning the oxygen permeability by means of the pH values and the sharp control of the thickness associated with this process. Therefore, based on the advantages outlined above, the LbL CS/CNs nanocomposite represents a promising oxygen barrier component in transparent flexible packaging materials and semi rigid tridimensional objects (bottles, trays, boxes and etc.). Based on our researches, we conclude that CNs leads to very promising applications in food packaging field and deserves to be further investigated in the future.

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
While there is extensive research regarding the impact of television on food choices, much less is focused on an instrument able to change beliefs at the point-of-purchase: packaging. This study aims to understand how food packaging can influence children‟s attitudes and purchase decisions towards healthier choices. Therefore, the appealing components of junk food packaging will be transferred to healthy food in order to understand its effect on children: Package Evaluation, Attention to Packaging, Attitude toward the Product, Perceived Healthiness, and Purchase Intention. To measure these variables, structured questionnaires were conducted to a sample composed by 408 Portuguese children aged between 10 and 14 years old from 5th to 9th grades. This study suggests that packaging can be a way to increase the appeal of healthy food to children and, consequently, improve their food choices, taking into consideration their values and preferences.

Considering the increasing competition between brands and products, packaging has become an important framing tool to influence customers' purchasing decisions. However, given the growing environmental concerns, zero packaging has emerged as a new practice to face the challenges of preventing and encouraging the use of packaging. With the introduction of zero packaging, marketers have been forced to reframe the practice of packaging, as artifacts used to create identification and familiarity to form a state of resonance have been removed. To extend the research of resonance within the marketing communication science, the study employed a qualitative approach to explore how food retailers are utilizing the framing concept of resonance as a means to revamp the traditional packaging into zero packaging. To reframe the practice of packaging, the study embraces the concept of cognitive and emotional resonance. The findings impose that food retailers need to create personal alignments with product artifacts, environmental values and containers. By reviewing the contextual marketing communication field, zero packaging, a third resonance was utilized to understand how the food retailers adequately attract, change and retain customers. Subsequently, affirmation was discovered as the key mechanism to achieve motivational resonance, by interfering with customers’ intrinsic and personalized values/desires.

Thesis (PhD)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Modified atmosphere packaging (MAP) is a dynamic process of altering gaseous composition inside a package. It relies on the interaction between the respiration rate (RR) of the produce, and the transfer of gases through the packaging material. These two processes are dependent on numerous factors such as storage temperature, film thickness and surface area, produce weight as well as free headspace within the pack. Therefore, in order to achieve the desired modified atmosphere in a given package, it is important to understand the three basic disciplines of MAP, namely produce physiology, polymer engineering, and converting technology. In this study the effects of storage conditions and duration on physiological responses i.e. respiration (RR) and transpiration rate (TR) of two pomegranate cultivars ‘Acco’ and ‘Herskawitz’, were investigated and mathematical models were developed to predict these physiological responses at given time and storage conditions. The result of this study showed that RR of whole pomegranate fruit was significantly higher than that of fresh arils, and that temperature had a significant impact on the RR of both whole fruit and fresh arils. The influence of time, and the interaction between temperature and time also had significant influences on RR of fresh pomegranate arils. These findings highlight the significance of maintaining optimal cold-storage condition for packaged arils or whole fruit along the supply chain. In addition, mathematical models based on the Arrhenius-type equation and the power function equation coupled with Arrhenius-type equation accurately predicted the effect of temperature and the influence of time and temperature on the RR of fresh pomegranate arils for both cultivars. Furthermore, the results of experimental and model prediction studies showed that both relative humidity (RH) and storage temperature had significant effects on TR. RH was the variable with the greatest influence on TR, and it was observed that arils were best kept at 5°C and 96% RH to maintain quality for 8 days. The applicability of the transpiration model developed was validated based on prediction of TR of pomegranate arils under different combinations of storage conditions. The model adequately predicted TR and provides a useful tool towards understanding the rate of water loss in fresh pomegranate arils as affected by storage conditions and duration. The effect of passive-MAP engineering design parameters as a function of produce weight contained, storage temperature and duration on fresh pomegranate arils was investigated. The result showed that produce weight of aril content, temperature and the interaction between temperature and time had slight but insignificant effects on measured physicochemical quality attributes. However, headspace gas concentration was significantly influenced by produce weight and storage temperature. Oxygen (O2) composition decline below 2% after day 3 and 5 at 15 and 10 ºC, respectively, while samples at 5 °C did not reach below 2% throughout the study. On the other hand, CO2 levels increased significantly during storage for all packaging conditions. This study showed the importance of a systematic approach to the design of optimal MAP systems. At lowest storage temperature the inability to achieve desired modified atmosphere (MA) required for optimal storage of arils despite the increase in produce weight, suggests that the use of active gas modification (gas flushing with recommended atmosphere) would be necessary. However, the present results show that at higher temperature macro/micro perforations would be required on the polymeric films used in the present study in order to avoid critical levels of O2 and CO2. The influence of passive MAP, storage temperature and duration on volatile composition and evolution of packaged pomegranate arils was investigated. The results showed that changes in aroma compounds were dependent on cultivar differences, storage condition and duration. Using GC-MS analysis of pomegranate juice HS-SPME extracts, a total of 18 and 17 volatiles were detected for ‘Herskerwitz’ and ‘Acco’, respectively. Furthermore, flavour life (7 days) was shorter than the postharvest life (10 days) for both cultivars. There was a decrease in volatile composition during the storage period (aldehydes < alcohols < esters) while the concentration (%) and composition of ethyl esters increased with storage time. These results highlight the need for a more precise definition of flavour shelf life for MApackaged pomegranate arils and other packaged fresh produce. The importance of maintaining optimal cold storage condition, selection of appropriate packaging materials and a systematic approach to the design and application of MAP systems has also been shown.
AFRIKAANSE OPSOMMING: Gemodifiseerde atmosfeer-verpakking (GAV) is ’n dinamiese proses waartydens die gassamestelling binne-in ’n verpakking gewysig word. Dit berus op die wisselwerking tussen die respirasietempo (RT) van die produkte en die oordrag van gasse deur die verpakkingsmateriaal. Hierdie twee prosesse is van verskeie faktore soos bergingstemperatuur, dikte van die film en oppervlakte, gewig van die produkte asook vry boruimte binne-in die pakkie afhanklik. Om dus die gewenste gemodifiseerde atmosfeer in ’n gegewe verpakking te verkry, is dit belangrik om die drie fundamentele dissiplines van GAV te begryp, naamlik produkfisiologie, polimeerontwerp, en omsettingstegnologie. In hierdie studie is die gevolge van bergingstoestande en -duur op fisiologiese reaksie, met ander woorde, respirasie- (RT) en transpirasietempo (TT) van twee geselekteerde granaatkultivars ‘Acco’ en ‘Herskawitz’, ondersoek en wiskundige modelle is ontwikkel om ons in staat te stel om hierdie fisiologiese reaksies by gegewe tyd- en bergingstoestande te voorspel. Die resultaat van hierdie studie het aangetoon dat die respirasietempo (RT) van heel granaatvrugte aansienlik hoër was as die RT van vars arils, en temperatuur het beduidende uitwerking op RT van beide heel vrugte en vars arils gehad. Die invloed van tyd, en die wisselwerking tussen temperatuur en tyd het ook ’n beduidende invloed op die RT van vars granaatarils gehad. Hierdie bevinding beklemtoon die belang van die handhawing van optimale koelbewaringstoestande vir verpakte arils of heel vrugte met die aanvoerketting langs. Daarbenewens wiskundige modelle wat gebaseer op die Arrhenius-tipe vergelyking en die magsfunksie-vergelyking gepaard met Arrhenius-tipe vergelyking, die uitwerking van temperatuur en die invloed van tyd en temperatuur op die RT van vars granaatarils vir beide kultivars onderskeidelik voldoende en akkuraat voorspel. Afgesien die resultate van eksperimentele en modelvoorspellings die studies aangetoon dat beide relatiewe humiditeit (RH) en bergingstemperatuur ’n beduidende uitwerking op TT het. RH was die veranderlike met die grootste invloed op TT, en it was waargeneem dat dit die beste was om arils teen 5°C en 96% RH te bewaar (8 dae). Die toepaslikheid van die transpirasiemodel wat ontwikkel is, is bevestig op grond van voorspelling van TT van granaatarils onder verskillende kombinasies van bergingstoestande. Die model het TT voldoende voorspel en sou ’n bruikbare instrument wees ten einde die waterverliestempo in vars granaatarils en ander vars produkte, soos deur bergingstoestande en duur beïnvloed, te begryp. Die uitwerking van passiewe-GAV ontwerpparameters as ’n funksie van gewig van die produkte, bergingstemperatuur en duur op vars granaatarils is ondersoek. Dit het aan die lig gebring dat gewig van die produkte, temperatuur en die wisselwerking tussen temperatuur en tyd ’n geringe maar onbeduidende uitwerking op gemete fisikochemiese gehalteeienskappe gehad het. Die gaskonsentrasie in die boruimte is betekenisvol beïnvloed deur gewig van die produkte en bergingstemperatuur. Die O2-samestelling het tot benede 2% gedaal na 3 en 5 dae by 15 en 10 ºC, onderskeidelik, terwyl monsters by 5 °C deur die studie heen nooit laer as 2% was nie. Aan die ander kant, CO2-vlakke het gedurende berging betekenisvol verhoog wat betref alle verpakkingstoestande. Hierdie studie het die belangrikheid van ’n sistematiese benadering by die ontwerp van ’n optimale GAV-stelsel aangetoon. By die laagste bergingstemperatuur dui die onvermoë om die gewenste gemodifiseerde atmosfeer (GA) wat vir optimale berging van arils benodig word, te verkry – ondanks die toename in die gewig van die produkte – daarop dat die gebruik van aktiewe gasmodifisering (gasspoeling met aanbevole atmosfeer) nodig sou wees. Egter die huidige uitslae aangetoon dat by hoër temperatuur, sou makro/mikroperforasies op die polimeerfilms wat gebruik word in die onderhawige studie egter nodig wees ten einde kritiese vlakke van O2 en CO2 te verhoed. Die invloed van passiewe GAV, bergingstemperatuur en duur op onstabiele samestelling en evolusie van verpakte granaatarils is ondersoek. Die resultate aangetoon dat veranderinge in aromaverbindings afhanklik was van kultivarverskille, bergingstoestande en duur. Met behulp van GC-MS-analise van granaatsap HS-SPME-ekstrakte, het ons ’n totaal van 18 en 17 vlugtige stowwe vir ‘Herskawitz’ en ‘Acco’, onderskeidelik bespeur. Verder het ons waargeneem dat die smaakleeftyd (7 dae) korter was as die na-oesleeftyd (10 dae) vir beide kultivar. Daar was ’n afname in vlugtige samestelling (aldehiede < alkohole < esters) terwyl die konsentrasie (%) en samestelling van etielesters het met bergingstyd verhoog. Hierdie resultate het die aandag gevestig op die behoefte aan ’n meer presiese definisie van geur-raklewe vir GA-verpakte granaatarils en ander verpakte vars produkte. Die belang van die handhawing van die optimale koelbewaringstoestand, seleksie van geskikte verpakkingsmateriaal en ’n sistematiese benadering tot die ontwerp van ’n optimale GAVstelsel, is ook beskryf.

This thesis explores novel DV -activated, oxygen-sensitive systems. Thus, photochemical versions of the thermal blue-bottle experiment are used to illustrate the kinetics of PET reactions in homogeneous and heterogeneous photochemistry; the former via the visible light photobleaching of a MB/TEOA solution, and fast recovery in air, and the latter via the DV photobleaching of MB in a Ti02/glucose aqueous dispersion, with slow recovery, but which can be catalysed by Pt. A novel, acetone-based, water-proof Ti02/MB/glycerol/SPS colorimetric oxygen indicating film that coats on hydrophobic polymers is prepared, and is readily photobl~ached but recovers slowly. The rate of photobleaching is dependent upon DV A irradiance, [glycerol], [Ti02] and [MB]. The kinetics of the dark recovery were dependent upon T, %02, and RH. Ethanol replaced acetone, and a Pt catalyst was introduced - i.e. a Pt-Ti02/MB/glycerol/SPS colorimetric oxygen indicator, printable by flexo printing, resulted. The indicator is readily photobleached and recovery times reduced, with linear dependence upon %Pt loading. The recovery kinetics are zero order with respect to [LMB](, moderately dependent upon temperature, and sensitive to relative humidity. Pigment particles (MB and DL-threitol coated onto Ti02) are prepared and extruded in LDPE, to create a water-proof, solvent-based O2 smart plastic film. The blue-coloured indicator is readily photobleached and recovers in ~2.5 days. The rate of photobleaching is dependent upon the irradiance of UV A light. The rate of recovery is dependent upon %02, relative humidity and temperature. A Ti02 colloid is prepared for use with MB in a colorimetric oxygen indicating ink. This ink is suitable for printing onto polyester film by a DOD PU printer. The blue-coloured indicator is readily photobleached and recovers in - 12 hours in ambient air. The rate of recovery is linearly dependent upon the %02, moderately dependent upon relative humidity at 21 "C, and reduced upon reducing temperature.

Packaging is a largely neglected object of enquiry in Human Geography and, indeed, the social sciences more broadly. Yet it forms a crucial element of almost all food systems and without such mundane objects these food systems would fail or function very differently. In turn, food systems, which rely on the continuous flow of packaging and food, are vital for enabling our increasingly mobile lives. This thesis thus investigates the multiple mobilities associated with food and drink packaging. The study forms part of a wider ‘mobilities turn’ in the social sciences and is structured in two parts. The first part concentrates primarily on how packaging shapes the movement of food. The second part focuses more on the ways in which packaged food shapes the mobilities of humans. However, both these aspects of packaging’s mobile life are not viewed as separate but rather as entangled and mutually dependent on each other. Throughout the thesis attention is paid to how packaging helps standardise the repetitive and anticipated mobilities of food and humans. It is, in other words, examined as an immutable mobile that ensures the smooth flows of food and people. Thus, in the first part of the thesis it is shown how packaging ensures the smooth flows associated with highly automated, industrialised and safe packaged food production and distribution. It also opens up the mobilities of packaging to elaborate upon the similarly regular and anticipated flows of packaging as raw materials. In the second part of the thesis attention is directed towards the patterns of human mobility that packaged food permits. However, while emphasis is placed on the role of packaging in standardising and stabilising interrelated food and human mobilities across Euclidean spaces, the thesis also begins to interrogate the topological complexities and molecular mobilities of packaging. While packaging can certainly be seen to permit the smooth and relatively unproblematic flows of food and people it may also, and from another theoretical perspective, be viewed as a fluid and vibrant technology. These topologically complex movements of packaging are explored in cases that show its fluid articulation as a barrier which has profound implications for the regulated mobilities of food. The vibrancy of packaging is also examined through its importance for mobile practices and its capacity to affect travellers.

The food packaging industry is a £300bn global industry growing at a rate of 12% per year and increasingly favouring polymer or polymer-based materials. This generates 58m tonnes of "plastic" packaging waste annually in the EU and poses significant challenges for management given existing legislative constraints and increasing concerns surrounding the environmental impacts. The government, consumers, food retailers and pressure groups are all driving the demand for biodegradable packaging from renewable resources that can be disposed of with reduced impacts to the environment. Green Peace has devised a pyramid classification system of "Poisonous Plastics", which ranks plastics in terms of their harmfulness to the environment. They are campaigning against the use of oil-based materials and advocating the take up of biodegradable materials. The market for biodegradable food packaging is expanding rapidly but is still in its early stages of development and has not reached a critical mass to achieve significant market penetration. This is predominantly due to a lack of suitable materials that meet all environmental, functional and economical requirements. Whilst the long-term solution requires continued efforts in materials research and development, in the shorter term, changing working practices can abate the environmental impact of the industry. This research project tackled the challenge of environmental packaging from several directions: A novel starch-based material was developed that would fill the current gap in the food packaging market and facilitate recovery of the used materials by home composting. Using the sponsoring organisation as a case study, it was proved that by changing working practices by increasing rework and re-processing waste material for use in lower grade applications, both manufacturing costs and environmental impact can be reduced, thus benefiting both industry and the environment. A Life Cycle Assessment of selected biopolymers and oil-based polymers confirmed Green Peace's damning view of PVC and highlighted the need to develop biopolymers further. A domestic composting study of a range of commercially available "biodegradable" polymer materials revealed that a number of biodegradable packaging materials may typically biodegrade well in industrial high-temperature composting systems but fail to biodegrade under a low-temperature home composting environment and thus alerted the potential pitfall in waste management of some biodegradable polymers.

Thesis (Master)--İzmir Institute of Technology, İzmir, 2005.
Keywords: Biopreservatives, antimicrobial enzymes, antioxidant proteins, edible films, functional packaging materials. Includes bibliographical references (leaves.88-101).

Food packaging should ensure the safety and quality of food, minimize spoilage and provide an easy way of storing and handling it. Barrier coatings are generally used to meet the demands placed on fibre-based food packages, as these have the ability to regulate the amount of gases that can enter them. Some gases are detrimental to food quality: oxygen, for example, initiates lipid oxidation in fatty foods. Using both experimental data and computer modelling, this thesis explains some aspects of how the structure of barrier coatings influences the mass transport of oxygen with the aim of obtaining essential knowledge that can be used to optimize the performance of barriers. Barrier coatings are produced from polyvinyl alcohol and kaolin blends that are coated onto a polymeric support. The chemical and physical structures of these barriers were characterized according to their influence on permeability in various climates. At a low concentration of kaolin, the crystallinity of polyvinyl alcohol decreased; in the thinner films, the kaolin particles were orientated in the basal plane of the barrier coating. The experimental results indicated a complex interplay between the polymer and the filler with respect to permeability. A computer model for permeability incorporating theories for the filled polymeric layer to include the polymer crystallinity, addition of filler, filler aspect ratio and surrounding moisture was developed. The model shows that mass transport was affected by the aspect ratio of the clay in combination with the clay concentration, as well as the polymer crystallinity. The combined model agreed with the experiments, showing that it is possible to combine different theories into one model that can be used to predict the mass transport. Four barrier coatings: polyethylene, ethylene vinyl alcohol + kaolin, latex + kaolin and starch were evaluated using the parameters of greenhouse gas emissions and product costs. After the production of the barrier material, the coating process and the end-of-life handling scenarios were analysed, it emerged that starch had the lowest environmental impact and latex + kaolin had the highest.
Food packaging is required to secure the safety and quality of food, as well as minimize spoilage and simplify handling. Barrier coatings are generally used to meet the demands placed on fibre-based food packages, as these have the ability to regulate the amount of gases that can enter them. Some gases are detrimental to food quality: oxygen, for example, initiates lipid oxidation in fatty foods. This thesis focuses on the mass transport of oxygen in order to gain deeper knowledge of, and thereby optimise, the performance of barrier coatings. This experimental study, together with computer modelling, characterized the structure of barrier materials with respect to the mass transport process. The performance of the barriers was evaluated based on the parameters of environmental impact and product costs. As the long-term aim is to use non-petroleum-based barrier coatings for packaging, these should be evaluated by assessing the properties of the material in question, its functionality and its environmental impact to provide more insight into which materials are desirable as well as to develop technology. The results from this study indicate that several parameters (the orientation, concentration and aspect ratio of the clay and the polymer crystallinity) influence the properties of a barrier. Using this knowledge, researchers and food packaging engineers can work toward improving and customising renewable barriers.
VIPP

The limited fossil fuels reserves, as well as serious pollution problems, have led to a continuously growing interest in the use of sustainable materials obtained from renewable sources for many different applications. Among these materials, biopolymers, and in particular the class of biopolyesters, could potentially replace traditional plastics. Their versatility and their ability to undergo degradation in the environment where they are disposed, is of particular interest both for food packaging (when recycling is not possible due to organic matter contamination as well as multi-layered structures) and for biomedicine, in case of temporary applications, such as controlled drug release or tissue engineering. If these materials hydrolyse in the human body, it is possible to avoid the removal of the implant through surgery. In this framework, aim of the present research project was the synthesis and characterization of new bio-based and biodegradable polyesters and copolyesters, with tailored properties in relation to the intended use, in the fields of food packaging, which is one of the most demanding in terms of plastic sources, and regenerative medicine, as it represents the new frontier of biomedicine. The synthetic routes adopted (i.e. two-step melt polycondensation, ring opening polymerization and chain extension) are solvent-free, simple and economic, and can be easily used for industrial scale-up. Monomers from renewable sources were preferred over the ones obtained from fossil fuels. Moreover, copolymerization turned out to be a winning strategy to modify the polymers of interest. Starting from polyesters, the aliphatic (i.e. polylactic acid, poly(butylene succinate), polymers containing cyclohexane ring) and aromatic ones (i.e. polymers containing furan and thiophene rings), all characterized by high stiffness and low degradation rates, it was possible to obtain more flexible materials with higher biodegradation rates, particularly suitable for soft tissue engineering and for the realization of flexible food packaging films.

During recent years there has been a growing interest towards emotion in consumer behavior. One of the innovative fields of the economic research is the neuromarketing approach. In this elaboration, it is going to be presented a neurometric study regarding the influence of emotion, interest and mental effort during the tactile exploration of a series of food packaging during the open, pour and close phases. Due to the very experimental nature of this research, the two very first trials will be presented followed by the main set up protocol with a sample of 24 young people with an average age of 25. Data have been gathered with EEG, HR and GSR devices together with some psychometrical work as a support. The research outcomes provide cerebral and emotional values towards different phases of usability of different food packaging. Given the uncertainty in the justification of the results, this research is intended as a pilot, by contributing to enhance forthcoming type of usability exploration studies. Keywords: Neuromarketing, Food Packaging, Emotional behavior, Touch, Usability, EEG, HR, GSR

Food products undergo numerous spoilage processes due to their highly perishable nature. Decreased food quality causes food borne diseases that affect the public health and well-being of the society. Therefore, manufacturers, retailers, consumers and regulatory agencies demand higher quality standards, and the adoption of strategies that enable the real time monitoring/traceability of the food quality throughout the supply chain. Recently the advances in the food packaging led to the development of active, intelligent and smart packaging materials able to improve the food quality, to increase the shelf life and to provide real time information about the condition of the food products. Although in the field numerous studies are continuously reported, there is still the need for the development of biocompatible, cost effective and highly performant systems easily scalable and applicable in everyday life. This thesis is focused on the development of active, and intelligent packaging biocomposite materials by utilizing functional fillers of natural origin, following cost effective, and easily scalable methods. Specifically, the first part of this study is focused on the modification of an already widely used polymer in food packaging, the low-density polyethylene, in order to improve its water vapor barrier properties and to transform it to a functional material with antioxidant properties, expanding thus its use in active packaging. This is succeeded by introducing into the polymer curcumin powder as filler, following the most common method for polyethylene processing used in industry, the melt processing. The developed composite shows excellent water vapor barrier and antioxidant properties making thus possible its use in active packaging for the shelf life increase of food products. In the second part of this study, an intelligent packaging porous indicator is developed by the combination of polyvinyl alcohol, microcrystalline cellulose and anthocyanins extracted from red cabbage. The specific material is able to indicate the food spoilage through a distinct color change that can be perceived by the naked eye and by non-expert users. In the third part of the present study, an smart packaging material is developed based on red cabbage powder and chitosan that combines the properties of both the active and intelligent packaging materials in a single system. The developed bioplastic presents excellent antioxidant activity, biodegradability and rapid color changes to the food’s pH fluctuations during the spoilage process indicating thus its quality deterioration.

Much of the interest concerning bioactive protein immobilization onto solid supports can be attributed to the many potential applications protein-modified surfaces may have in the area of biotechnology. Immobilized bioactive proteins (e.g. antibodies, enzymes) have been used in countless immunoassays, as well as in clinical analysis and diagnostics, in biosensors, and in various industrial applications, including food processing. In this frame, this PhD thesis research project aimed at developing strategies to immobilize food-relevant bioactive proteins onto various solid supports, and at exploiting the interactions between the proteins and the solid matrices considered in this peculiar project to design either innovative packaging materials or novel nanotech-based analytical tools. Within the overall objective mentioned above, this project was subdivided into the following activities: 1. preparation of an antimicrobial biodegradable packaging material by binding lysozyme onto papers opportunely modified with polyelectrolytes; 2. preparation of biofunctionalized magnetic nanoparticles by binding specific food bioactive proteins to a conveniently activated dextran coating on the particle surface, for cellular targeting of conjugates; 3. preparation of magnetic nanotracers for addressing molecular recognition events, and use of the nanotracers to improve current analytical protocols. Novel food processing and new packaging strategies are being developed as a response to both consumer demand for and industrial trends towards mildly preserved, tasty, and convenient food products with prolonged shelf-life and controlled quality. Globalization of the food trade and recent food-borne microbial outbreaks are driving forces in the search for innovative ways to inhibit microbial growth in foods while maintaining quality, freshness, and safety. In this frame, one of the most innovative developments in the area of food packaging is the design of antimicrobial biopolymer-based active packaging materials incorporating biocides into or onto the surface of polymers themselves. In our studies, we addressed the interactions between charged polysaccharides and lysozyme, monitoring the protein structural changes and rearrangements consequent to noncovalent bonds with the polysaccharides. Lysozyme was incubated for different times and at different temperatures with soluble carboxy-methyl cellulose (CMC), and polygalatturonic acid (PGA), in the presence/absence of salts (NaCl), non-ionic chaotropes (urea), and anionic detergents (sodium dodecyl sulphate). The various systems were then analysed by a number of spectroscopic methodologies that demonstrated that the charged polyelectrolytes do not impair the structural and functional properties of lysozyme. Tryptophan fluorescence measurements showed that soluble CMC improves the thermal stability of the tertiary structure of lysozyme above 60°C, and has little if any effect on the stability of its secondary structure, as demonstrated by far-UV circular dichroism measurements. This data paved the way to the addition of CMC and PGA to paper-based packaging materials intended to incorporate lysozyme as antimicrobial not only because this improves the incorporation yield (mainly due to electrostatic interactions) and allows modulation of protein release, but also because it results in stabilization and preservation of the protein structure and activity during drying at 100°C, mimicking the heating steps in the paper making process itself, and would likely prolong the operative shelf-life of the resulting active packaging. The second part of this project dealt with the preparation of nanotechnological food-related applications. Nanotechnology is an emerging multidisciplinary field of applied science and technology which provides the methods and a sound framework for understanding and developing materials and products with at least one dimension smaller than 100 nm. Advancement in processes for producing nanostructured materials has led to the development of biocompatible magnetic supports with potential biochemical and biotechnological applications. This kind of support is generally synthesized by encapsulating magnetic materials within a polymeric layer. The interest for magnetic nanosupports is not only limited to the obvious ease of their separation under micro- and nanofluidic conditions, or to their entrapment in coatings and films. Most relevant is the fact that nanostructures can be conjugated to biologically active molecules, including hormones, antibodies, and various peptides, taken up by cells, and circulated among tissues expressing their cognate receptors. Given their intrinsic magnetism, and the perturbation induced on nuclear magnetism by other ferromagnetic species, magnetic nanoparticles may be used as tracers in NMR and imaging-NMR experiments, are detectable under appropriate conditions in standard transmission electron microscopy, and have demonstrated their potential in sensing a number of reversible molecular interactions, such as protein-protein, DNA-DNA, protein-small molecule, and enzyme reactions. In particular, we considered the pathway to design and prepare nanotracers by covalently binding food-related bioactive proteins to dextran-coated iron oxide magnetic nanoparticles (NP). The particles, with a diameter of 70-90 nm, were synthesized by chemical co-precipitation from an aqueous solution of Fe3+, Mn2+, and Zn2+ chloride, and then coated with dextran. Proteins considered in our studies included food allergens (betalactoglobulin), antibodies to food proteins (anti-gliadin IgGs), and enzymes. Trypsin was immobilized since it provides ease of quantification, and because of its usefulness in interactomics studies. RNAse was also conjugated to NP and used as structural probe by extending to NP conjugates some physico-chemical methodologies already used for characterization of the free enzyme. NP were modified either by epoxydation, followed by amination and succinylation, or by carboxymethylation in order to introduce on dextran carboxyl groups that were then converted by carbodiimide into reactive esters, allowing the subsequent coupling with different specific food proteins added in the reaction mixture. The successful coupling to the NP of all the proteins used in this project was assessed and measured by a number of different procedures. Microscopic, immunological, enzymatic, and physico-chemical approaches were used, whereas spectrofluorimetric techniques have proven not to be useful due to the high scattering and absorbance of the iron-oxide based particles that prevented us from obtaining reliable results. Size and morphology of both unmodified and functionalized NP were characterized by transmission electron microscopy. These measurements showed that aggregation phenomena were induced by both dextran activation approaches and, in particular, by the various centrifugation steps required in the functionalization process, although fresh unmodified NP also tend to form aggregates. However, the procedure based on carboxymethylation resulted in the lowest extent of particle aggregation. Dot blotting with specific antibodies, followed by immunoenzymatic detection of the bound antibodies, demonstrated the actual presence of betalactoglobulin (BLG) on the conjugated NP. Competitive ELISA tests performed by using conjugates between carboxymethylated NP and BLG led us to measure a coupling yield of 20 μg protein per mg NP. This indicates that each NP, assuming an average mass of 1 MDa for a particle of the given composition and diameter, binds one bioactive protein molecule. The resulting conjugates were then used to address the issue of allergen recognition and subsequent uptake by cell model systems. In particular, human monocytes were incubated with unmodified and conjugated NP and then separated by MACS® technology, that uses a magnetic field strong enough to retain cells that integrate even the smallest amount of magnetic material. We could therefore study the uptake of both kinds of particles by this peculiar cell line: BLG-conjugated NP are endocytosed in higher amounts and faster with respect to non-conjugated NP. Indeed, the presence of bioactive BLG favors particle endocytosis, although a certain extent of particle internalization was assessed and may be due to non specific interactions between the NP and cell membranes. Both kinds of NP were also used for assessing via different microscopy techniques (optical, fluorescence and electron microscopy) the uptake by Triticum durum sprouts, and the particle effects on model animal cell systems. Tests aimed at assessing the citotoxicity of unmodified and conjugated NP showed that the viability of both differentiated HT-29 and Caco-2 cells after various times of incubation with the NP was close to that of control untreated cells, indicating the full biocompatibility of these particles with these in vitro intestinal cellular models. This result was confirmed by both the cell proliferation rate and the levels of apoptotic markers that were unaffected by 24 hours incubation with the same NP. Trans-Epithelial Electric Resistance measurements were performed on Caco-2 cells differentiated towards an epithelial structure, and demonstrated that incubation with unmodified and conjugated NP increases the TEER. This reveals a direct effect on the paracellular permeability of intestinal cells by the NP that might act as protective agents against foreign molecules that are potentially dangerous for the integrity of the epithelial barrier made by the cellular tight junctions. The same immobilization approaches described above were used to develop magnetic nanotracers that may be used in interactomics studies for assessing molecular recognition events occurring in the complex machineries involved in cofactor and protein assembly. We immobilized commercial anti-gliadin IgG to the NP, and we subsequently performed, as test of protein immobilization, dot-blotting and immunoprecipitation experiments in the presence of gliadins that showed that anti-gliadin IgG coupled to the NP were able to recognize bioactive protein epitopes after the binding procedure. The coupling ratio of both our functionalization approaches was also estimated by conjugating analytical-grade trypsin to the dextran-coated NP, and by evaluating the immobilized enzyme activity on synthetic (benzoyl-L-arginine p-nitroanilide) and complex substrates (caseins). Although yields were in all cases quite low, they compare well with those reported for equivalent procedures reported in the literature. Most relevant is the fact that carboxymethylation resulted in a higher protein/particle ratio that was comparable to that obtained by ELISA in the case of BLG. Moreover, NP-trypsin conjugates were used in interactomics experiments and succeeded in recovering a trypsin inhibitor from a protein solution paving the way to their use as nanosized probes for the development of innovative analytical food-related tools. Possible changes in the thermal stability of the NP-bound RNase were investigated by DSC experiments that demonstrated that the presence of NP did not alter the denaturation curve of RNase, although the amount of bound RNase was too low to detect a differential heat flow after washing away unbound protein. These studies pave the way to the use of the conjugates between magnetic NP and bioactive proteins as biological tracers in order to monitor via appropriate techniques the intracellular and/or intratissutal path of specific proteins (with particular reference to food allergens, to food-derived compounds of known toxicity, as well as to protein-derived materials that could act as nutraceuticals), and to elucidate specific complex cell machineries that involve specific interactions between proteins and other biomolecules (with a special focus on systems that have been previously studied in our lab).

The object of this research was to develop a retort for research and development of thermal processes which use common commercial thermal processing techniques. An FMC 500W laboratory sterilizer, designed to operate with an FMC weir product racking system, was modified for conventional steam, positive flow steam/air and water immersion/air overpressure thermal processing of foods in thin profile retortable packages. The research included the modification of the retort plumbing and the fabrication of a set of product trays and a racking system. The completed system was tested for temperature distribution and stability, and heat transfer distribution for each processing mode. The latter was achieved by comparing the heat penetration parameters calculated from the centerpoint temperature histories of conduction heating teflon transducers.
Applied Science, Faculty of
Graduate

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

This report focuses on the study of nanomaterials as a packaging material for the food industries. Reviews were carried out and the various properties exhibited by various nanomaterial used in the packaging industry were looked into. An investigation was also done on carbon nanotubes which are used to a large extent as reinforcing materials in the development of new class of nanocomposites. This report also traces the cause of sustainability problems associated with the use of nanomaterials in the food packaging industry. It analyzes and extrapolates the prospect of additional capabilities that human may gain from the development of nanomaterial in the food industry in order to ascertain environmental sustainability.
Kungsmarksvagen 71 Room 1329, 371 44, karlskrona,Sweden. Tel No: +46-737154801

Industrial applications of computer vision often utilize traditional image processing techniques whereas state-of-the-art methods in most image processing challenges are almost exclusively based on convolutional neural networks (CNNs). Thus there is a large potential for improving the performance of many machine vision applications by incorporating CNNs. One such application is the classification of juice boxes with straws, where the baseline solution uses classical image processing techniques on depth images to reject or accept juice boxes. This thesis aim to investigate how CNNs perform on the task of semantic segmentation (pixel-wise classification) of said images and if the result can be used to increase classification performance. A drawback of CNNs is that they usually require large amounts of labelled data for training to be able to generalize and learn anything useful. As labelled data is hard to come by, two ways to get cheap data are investigated, one being synthetic data generation and the other being automatic labelling using the baseline solution. The implemented network performs well on semantic segmentation, even when trained on synthetic data only, though the performance increases with the ratio of real (automatically labelled) to synthetic images. The classification task is very sensitive to small errors in semantic segmentation and the results are therefore not as good as the baseline solution. It is suspected that the drop in performance between validation and test data is due to a domain shift between the data sets, e.g. variations in data collection and straw and box type, and fine-tuning to the target domain could definitely increase performance. When trained on synthetic data the domain shift is even larger and the performance on classification is next to useless. It is likely that the results could be improved by using more advanced data generation, e.g. a generative adversarial network (GAN), or more rigorous modelling of the data.

This thesis reports the systematic approaches to overcome the key drawbacks of the pure PHBV, namely low crystallisation rate, tensile strength, ductility, melt viscosity, thermal stability and high materials cost. The physical, mechanical, thermal, and rheological properties of the pure PHBV were studied systematically first to lay a solid foundation for formulation development. The influence of blending with other biopolymers, inclusion of filler, and chain extender additives in terms of mechanical properties, rheology, thermal decomposition and crystallization kinetics were then followed. Creating lightweight structures by foaming is considered to be one of the effective ways to reduce material consumption, hence the reduction of density and morphology of PHBV-based foams using extrusion foaming technique were studied comprehensively in terms of extrusion conditions (temperature profiles, screw speed and material feeding rate) and the blowing agent content. The material cost reduction was achieved by adding low-cost filler (e.g. CaCO3) and reduction of density by foaming. The thermal instability was enhanced by incorporation of chain extender (e.g. Joncryl) and blending with a high thermal stability biopolymer (e.g. PBAT). The polymer blend also improved the ductility. Adding nucleation agent enhanced the crystallization rate to reduce stickiness of extruded sheet. The final formulation (PHBV/PBAT/CaCO3 composite) was successfully extruded into high quality sheet and thermoformed to produce prototype trays in an industrial scale trial. The effect of the extrusion conditions (temperature profiles, screw speed and material feeding rate) and the blowing agent content are correlated to the density reduction of the foams. 61 and 47 % density reduction were achieved for the commercial PHBV and the PHBV/PBAT/CaCO3 composite respectively and there exists further scope for more expansion if multiple variable optimisation of the conditions are carried out.