Academic literature on the topic 'Food packaging film'

Polymeric films for active food packaging have been playing an important role in food preservation due to favorable properties including high structural flexibility and high property tunability. Over the years, different polymeric active packaging films have been developed. Many of them have found real applications in food production. This article reviews, using a practical perspective, the principles of designing polymeric active packaging films. Different factors to be considered during materials selection and film generation are delineated. Practical considerations for the use of the generated polymeric films in active food packaging are also discussed. It is hoped that this article cannot only present a snapshot of latest advances in the design and optimization of polymeric active food packaging films, but insights into film development to achieve more effective active food packaging can be attained for future research.

Recently, consumers have been increasingly inclined towards natural antimicrobials and antioxidants in food processing and packaging. Several bioactive compounds have originated from natural sources, and among them, grapefruit seed extract (GSE) is widely accepted and generally safe to use in food. GSE is a very commonly used antimicrobial in food; lately, it has also been found very effective as a coating material or in edible packaging films. A lot of recent work reports the use of GSE in food packaging applications to ensure food quality and safety; therefore, this work intended to provide an up-to-date review of GSE-based packaging. This review discusses GSE, its extraction methods, and their use in manufacturing food packaging film/coatings. Various physical and functional properties of GSE-added film were also discussed. This review also provides the food preservation application of GSE-incorporated film and coating. Lastly, the opportunities, challenges, and perspectives in the GSE-added packaging film/coating are also debated.

Recent uses of titanium dioxide (TiO2) have involved various applications which include the food industry. This study aims to develop TiO2nanoparticle-coated film for potential food packaging applications due to the photocatalytic antimicrobial property of TiO2. The TiO2nanoparticles with varying concentrations (0–0.11 g/ 100 mL organic solvent) were coated on food packaging film, particularly low density polyethylene (LDPE) film. The antimicrobial activity of the films was investigated by their capability to inactivateEscherichia coli(E. coli) in an actual food packaging application test under various conditions, including types of light (fluorescent and ultraviolet (UV)) and the length of time the film was exposed to light (one–three days). The antimicrobial activity of the TiO2nanoparticle-coated films exposed under both types of lighting was found to increase with an increase in the TiO2nanoparticle concentration and the light exposure time. It was also found that the antimicrobial activity of the films exposed under UV light was higher than that under fluorescent light. The developed film has the potential to be used as a food packaging film that can extend the shelf life, maintain the quality, and assure the safety of food.

Edible and active packaging are attractive for use in food packaging applications due to their functionality and sustainability. This research developed new antioxidant active food packaging materials from cassava starch/gelatin (7:3 w/w) composite films with varied antioxidant types (quercetin and tertiary butylhydroquinone (TBHQ)) and concentrations (0–200 mg/200 mL film-forming solution) and evaluated their properties. Antioxidant addition altered the mechanical and barrier properties of the films. At 34% relative humidity (RH), increasing the concentration of quercetin increased the tensile strength and decreased the elongation at break of the composite films. Increasing quercetin and TBHQ contents increased the film water solubility and water vapor transmission rate. Intermolecular interactions between the antioxidants and films, as found in Fourier transform infrared (FT-IR) spectra and XRD micrographs, were related to the changed film functionalities. In food application studies, the cassava starch/gelatin films containing quercetin and TBHQ retarded the oxidation of lard (more than 35 days) and delayed the redness discoloration of pork. Cassava starch/gelatin composite films integrated with quercetin and TBHQ can be utilized as active packaging that delays oxidation in foods.

Chitosan-zinc oxide (C-ZnO) films were prepared by a simple one pot procedure. In order to investigate the property of C-ZnO films, two composite films were prepared by varying the loading of ZnO and compared with pure chitosan film (C). The films were characterized by various techniques such as FTIR, DSC, tensile, contact angle and water vapour permeability. FTIR analysis showed changes in hydrogen bonds band at 3351 cm-1 compared to pure chitosan film. The incorporation of ZnO in chitosan films increased the contact angle by 30.5% in C-ZnO1.0 film while water vapour transmission rate decreased by 7.8% compared to C film. From the tensile test, C-ZnO0.5 and C-ZnO1.0 films were found to be much superior by 1.5 times and 2.5 times respectively compared to bare chitosan film. Larger inhibition ring (by 47%) was exhibited by C-ZnO1.0 as compared to C-ZnO0.5 when tested against S.aureus. From the results, it is displayed that the incorporation of zinc oxide to chitosan improve their properties which also shown the potential to become a candidate for food active packaging.

Background: The use of biopolymer packaging materials for freezing and low-temperature storage keeps food items qualitative and safe. It also reduces environmental pollution caused by biopolymer petrolic materials that have a long biodegradation period. Aim: It is necessary to find out the possibility of using biopolymer film “CornBag” in the low-temperature preservation of food items. Methods: Freezing and low-temperature storage of polymer films were carried out in chest freezers Liebherr LGT 2325 Mediline and VESTFROST Solutions VT 078. The tensile testing machine Labthink XLW (M) measured physical and mechanical properties. Results and Discussion: The article covers the results of researching low-temperature effects on physical and mechanical properties (tensile strength and tensile strength at break) of biopolymer film “CornBag” derived by polymerizing starch from corn and sweet potato, low-temperature action having been performed in the range of -60 º? to -20 ºC for 90 days. It has been found that during the storage period, the action of low temperatures does not reduce the strength properties of the biopolymer film significantly. Changes in the strength properties of the biopolymer film and the biaxially oriented polypropylene film under long-term effects of low temperatures have been differentially analyzed. Changes in tensile strength at the break having been analyzed, stretch diagrams of the biopolymer and biaxially oriented films were obtained. It has been concluded that the strength properties of biopolymer film “CornBag” decline to no more than 12.5 % after 90-day storage under -60 ºC. Conclusions: The biopolymer film is equal to the biaxially oriented polypropylene film and can be recommended for freezing and low-temperature storage of food items.

Suitable packaging material in combination with high-pressure processing (HPP) can retain nutritional and organoleptic qualities besides extending the product’s shelf life of food products. However, the selection of appropriate packaging materials suitable for HPP is tremendously important because harsh environments like high pressure and high temperature during the processing can result in deviation in the visual and functional properties of the packaging materials. Traditionally, fossil-based plastic packaging is preferred for the HPP of food products, but these materials are of serious concern to the environment. Therefore, bio-based packaging systems are proposed to be a promising alternative to fossil-based plastic packaging. Some studies have scrutinized the impact of HPP on the functional properties of biopolymer-based packaging materials. This review summarizes the HPP application on biopolymer-based film-forming solutions and pre-formed biopolymer-based films. The impact of HPP on the key packaging properties such as structural, mechanical, thermal, and barrier properties in addition to the migration of additives from the packaging material into food products were systemically analyzed. HPP can be applied either to the film-forming solution or preformed packages. Structural, mechanical, hydrophobic, barrier, and thermal characteristics of the films are enhanced when the film-forming solution is exposed to HPP overcoming the shortcomings of the native biopolymers-based film. Also, biopolymer-based packaging mostly PLA based when exposed to HPP at low temperature showed no significant deviation in packaging properties indicating the suitability of their applications. HPP may induce the migration of packaging additives and thus should be thoroughly studied. Overall, HPP can be one way to enhance the properties of biopolymer-based films and can also be used for packaging food materials intended for HPP.

This review discusses the potential application of gelatin-based film as biodegradable food packaging material from various types of gelatin sources. The exploitation of gelatin as one of the biopolymer packaging in the food industry has rising interest among researchers as the world becomes more concerned about environmental problems caused by petroleum-based packaging and increasing consumer demands on food safety. Single gelatin-based film properties have been characterized in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as thickness, color, and biodegradability were much influenced by total solid contents in each film. While, for mechanical and light barrier properties, poultry-based gelatin films have shown better properties compared to mammalian and marine gelatin films. This paper detailed the information on gelatin-based film characterization in comparison with active and intelligent gelatin-based composite films. The physical properties of gelatin-based film such as color, UV-Vis absorption spectra, water vapor permeability, thermal, and moisture properties are discussed along with their mechanical properties, including tensile strength and elongation at break.

Active packaging material has been used in the food industry to maintain the quality of packaged foods. The use of conventional polymers has serious environmental consequences due to improper disposal or recycling methods. Therefore, active packaging films based on biopolymers have been developed due to their excellent biocompatibility, degradability, and eco-friendliness. Amongst all essential oils, grape seed oil is considered to be a promising antimicrobial agent. It comprises large quantities of flavonoids, tocopherols, and other antimicrobial compounds. Grape seed essential oil has good antimicrobial and antioxidant activity. As a film, it is used to preserve food items such as poultry products, fish, and tomatoes. This work aimed to develop a polybutylene adipate terephthalate (PBAT) biocomposite film incorporated with natural grape seed essential oil (GEO) in addition to silica nanoparticles (SiO2 NPs) using the solution casting process. To achieve the desired packaging properties of the prepared PBAT-based film, the concentrations of grape seed essential oil as a plasticizer and nanosilica as a filler material were varied. The optical, physical, barrier, mechanical, surface hydrophobicity, and antibacterial properties of the PBAT/GEO/SiO2NP films were assessed. The FT-IR and XRD results indicated that GEO had effective miscibility with the PBAT/SiO2NP matrix. The addition of GEO increased the film flexibility, opacity, and antimicrobial activity, but the incorporation of SiO2NPs in the PBAT/GEO blend increased the tensile strength, thermal stability, and antimicrobial activities. The PBAT/GEO/SiO2NP films exhibited excellent antibacterial activity against food spoilage microorganisms. Finally, due to improved antimicrobial activities, film flexibility, optical, and heat resistance properties, the PBAT/GEO/NP nanocomposite films were found to have high potential for usage in active food packaging applications.

L'attuale tendenza nel confezionamento degli alimenti è orientata alla sostituzione di polimeri non biodegradabili a base di petrolio con materiali di imballaggio ecologici e che possano prolungare anche la shelf-life degli alimenti. In questo contesto, il progetto Ph.D. ha preso in considerazione lo sviluppo di film misti a base di chitosano arricchiti con composti antimicrobici naturali (oli essenziali) e di sintesi (etil lauroil arginato) per applicazioni di confezionamento alimentare sostenibile. L'intero progetto è stato diviso in cinque parti principali. Il capitolo I presenta una breve introduzione sui recenti progressi dei film costituiti da miscele a base di chitosano. Il motivo per cui è stato scelto il chitosano come biopolimero principale in questo studio e nella revisione della letteratura riguardante la miscelazione del chitosano con altri biopolimeri è stata descritta. Nel capitolo II, i film attivi a base biologica e doppio strato sono sviluppati mediante tecnica solvent casting, usando chitosano e gelatina come biopolimeri, glicerolo come plastificante e etil lauroil arginato (LAE) come composto antimicrobico. I risultati hanno mostrato che i film di miscelazione presentavano una resistenza alla trazione e un modulo elastici più elevati e una permeabilità al vapore acqueo inferiore rispetto ai film a doppio strato (p <0,05). I film bilayer hanno dimostrato un’efficace barriera contro la luce UV e valori di trasparenza inferiori (p <0,05). Gli spettri FT-IR hanno indicato la presenza di interazioni tra chitosano e gelatina, in particolare interazioni elettrostatiche e formazione di legami idrogeno. Tuttavia, l'aggiunta di LAE non ha interferito nella struttura della rete. I film attivi contenenti LAE (0,1%, v / v) hanno inibito la crescita di quattro patogeni alimentari tra cui Listeria monocytogenes, Escherichia coli, Salmonella typhimurium e Campylobacter jejuni. Nel capitolo III, sono sviluppati film a base di miscela chitosano-gelatina arricchita con cannella, citronella, chiodi di garofano rosa, noce moscata e oli essenziali di timo (1%, v / v) e le loro proprietà fisiche, ottiche, meccaniche, di barriera all'acqua e microstrutturali sono state valutate per applicazioni di confezionamento alimentare attivo. I risultati hanno confermato le interazioni intermolecolari tra i gruppi funzionali degli oli essenziali con i gruppi idrossile e amminico della rete di film di chitosano-gelatina. L'incorporazione di diversi oli essenziali ha migliorato notevolmente le proprietà di barriera UV. I film sviluppati, con particolare riguardo a quelli integrati con l'olio essenziale di timo, erano efficaci contro i quattro comuni patogeni alimentari testati. Il capitolo IV si concentra sullo sviluppo di film attivi basati sulla miscelazione di biopolimeri naturali (chitosano) e sintetici (polivinilico alcool). Sono stati sviluppati film in miscela di chitosano, polivinil alcool e LAE, incorporato in questi film a diverse concentrazioni (1-10%, p / p). I risultati hanno mostrato che alti livelli di LAE hanno influenzato negativamente sulle proprietà di barriera meccanica e permeabilità all'acqua. Anche in questo caso film attivi sviluppati erano efficaci contro quattro agenti patogeni alimentari testati. Il capitolo V rappresenta la conclusione di questa tesi, e presenta una sintesi dei punti salienti dei risultati importanti, ottenuti in questo studio.
The current trend in food packaging is oriented towards the substitution of non-biodegradable petroleum-based polymers by packaging materials that are eco-friendly and can prolong the food shelf life as well. In this context, this Ph.D. project aims to the development of chitosan-based blend films enriched with natural (essential oils) and synthetic (ethyl lauroyl arginate) antimicrobial compounds for sustainable food packaging applications. The overall project has been divided into five main parts. The brief description of each chapter is presented here: Chapter I presents a brief introduction to the recent advances of chitosan-based blend films for food packaging applications. The reason for selecting chitosan as the main biopolymer in this study and literature review concerning blending chitosan with other biopolymers has been described. Chapter II aims to develop blend and bilayer bio-based active films by solvent casting technique, using chitosan and gelatin as biopolymers, glycerol as a plasticizer and ethyl lauroyl arginate (LAE) as an antimicrobial compound. The results showed that blend films had higher tensile strength and elastic modulus and lower water vapor permeability than bilayer films (p<0.05). Bilayer films demonstrated as effective barriers against UV light and showed lower transparency values (p<0.05). FT-IR spectra indicated that interactions existed between chitosan and gelatin due to electrostatic interactions and hydrogen bond formation. However, the addition of LAE did not interfere in the network structure. Active films containing LAE (0.1%, v/v) inhibited the growth of four food bacterial pathogens including Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, and Campylobacter jejuni. Chapter III focuses to develop films based on chitosan-gelatin blend enriched with cinnamon, citronella, pink clove, nutmeg, and thyme essential oils (1%, v/v) and evaluating their physical, optical, mechanical, water barrier and microstructural properties for active food packaging applications. The results confirmed intermolecular interactions between functional groups of the essential oils with the hydroxyl and amino groups of the chitosan-gelatin film network. The incorporation of different essential oils notably improved the UV barrier properties. The developed films, with special regards for those including thyme essential oil, were effective against four common food bacterial pathogens. Chapter IV aims to develop active films based on blending chitosan and polyvinyl alcohol enriched with LAE at different concentrations (1-10%, w/w). The results showed that high LAE levels negatively affected mechanical and water barrier properties. Addition of LAE improved UV barrier properties. The developed active films were effective against four common food bacterial pathogens.

Les plastiques sont aujourd'hui des matériaux ubiquitaires utilisés dans tous les aspects de notre vie quotidienne, en particulier pour l'emballage alimentaire. Cependant, après usage, les plastiques sont une source de pollution de notre environnement naturel. Certains plastiques biodégradables et biosourcés sont déjà disponibles sur le marché, comme l’acide polylactique (PLA), mais ils présentent des performances inférieures. Ce travail de thèse vise à: 1) étudier la stabilité des films de PLA dans diverses conditions de température, d'humidité relative, de pH, d'exposition à des liquides ou à des vapeurs... 2) mieux comprendre l'impact de certains procédés industriels tels que les traitements corona ou pressage à chaud sur le PLA 3) combiner le PLA à des couches de gluten de blé afin de produire des complexes ayant des propriétés barrière plus élevées.Les films de PLA ont été produits par la société Taghleef Industries sur demande et avec des traitements de surface spécifiques, comme le traitement Corona. Des films et des enductions à basede gluten de blé ont été développés à l’échelle laboratoire ainsi que des complexes tricouches PLA- gluten-PLA. Les propriétés physiques et chimiques des films ont été étudiées par différentes techniques issues des sciences des matériaux et des aliments ont été utilisées, telles que l’analyse enthalpique différentielle (DSC), l'analyse thermogravimétrique (TGA), la chromatographie d'exclusion de taille (SEC), la microscopie de force atomique (AFM), la microscopie électronique (SEM), la spectroscopie infrarouge à transformée de Fourier (ATR-FTIR) et la spectroscopie de rayons X (XPS). Les propriétés fonctionnelles telles que la perméabilité à la vapeur d'eau, à l'oxygène (O2), au dioxyde de carbone (CO2) ou à l'hélium (He), la sorption de gaz et de vapeurs, les propriétés mécaniques et de surface ont également été étudiées.Exposés au CO2, les films de PLA présentent une isotherme de sorption linéaire avec l’augmentation de pression. Cependant les modifications physiques et chimiques induites à des pressions élevées n'affectent pas son utilisation dans le domaine d’application alimentaire. Au contraire, lorsque les films de PLA sont exposés à l'humidité à l'état liquide ou vapeur, leur dégradation survient après deux mois à 50 ° C (essai accéléré) suite à son hydrolyse. Cette détérioration chimique, mise en évidence par une diminution significative de la masse molaire, entraine une perte de transparence, mais également par une augmentation de la cristallinité. Par ailleurs, le pH n'affecte pas le taux d'hydrolyse, ce qui est d'un intérêt essentiel pour conditionner des aliments humides.Les films à base gluten de blé ont été choisis pour leurs propriétés de barrière élevées lorsque l’humidité relative reste faible. L'incorporation de lipides n'a pas apporté d'amélioration de leurs performances barrières. Cependant, l'utilisation d’un procédé d’homogénéisation à haute pression a permis une meilleure dispersion du gluten, ce qui a conduit à des films plus homogènes ayant ainsi de meilleures propriétés fonctionnelles. Ces conditions ont donc été retenues pour réaliser des complexes à 3 couches par assemblage d'une couche de gluten de blé entre deux couches de PLA en utilisant un pressage à chaud (10 MPa, 130 ° C, 10 min).La technologie de pressage à chaud montre une forte influence sur les films de PLA, de gluten et sur les tricouches. Elle induit une cristallisation accrue du PLA, ce qui augmente ses propriétés de barrière d'environ 40% et 60%, respectivement pour l'eau et l'oxygène. Cela masque par contre l’effet du traitement corona. D’autre part, le pressage à chaud induit une restructuration du réseau de gluten qui améliore les propriétés de barrière aux gaz des complexes, mais provoque aussi une évaporation de l'eau à l'interface gluten / PLA défavorable à l’adhésion des couches (...)
Poly(lactic acid) (PLA) is a biodegradable and renewable polyester, which is considered as the most promising eco-friendly substitute of conventional plastics. It is mainly used for food packaging applications, but some drawbacks still reduce its applications. On the one hand, its low barrier performance to gases (e.g. O2 and CO2) limits its use for applications requiring low gas transfer, such as modified atmosphere packaging (MAP) or for carbonate beverage packaging. On the other hand, its natural water sensitivity, which contributes to its biodegradation, limits its use for high moisture foods with long shelf life.Other biopolymers such as wheat gluten (WG) can be considered as interesting materials able to increase the PLA performances. WG is much more water sensitive, but it displays better gas barrier properties in dry surroundings. This complementarity in barrier performances drove us to study the development of multilayer complexes PLA-WG-PLA and to open unexplored application scenarios for these biopolymers.This project was thus intended to better understand how food components and use conditions could affect the performances of PLA films, and how these performances could be optimized by additional processing such as surface modifications (e.g. corona treatment and coatings).To that aim, three objectives were targeted:- To study the stability of industrially scale produced PLA films in contact with different molecules (CO2 and water) and in contact with vapour or liquid phases, with different pH, in order to mimic a wide range of food packaging applications.- To better understand the impact of some industrial processes such as corona or hot press treatments on PLA.- To combine PLA with WG layer to produce high barrier and biodegradable complexes.Different approaches coming from food engineering and material engineering were adopted. PLA films were produced at industrial scale by Taghleef Industries with specific surface treatments like corona. Wheat gluten films, coatings and layers were developed and optimized at lab scale as well as the 3-layers PLA-WG-PLA complexes. Different technologies able to mimic industrial processes were considered such as hot press, high pressure homogenization, ultrasounds, wet casting and spin coating. The physical and chemical properties of PLA films were then studied at the bulk and surface levels, from macroscopic to nanometer scale. The functional properties like permeability to gases (e.g. O2 and CO2) and water, gas and vapour sorption, mechanical and surface properties were also investigated.Exposed to CO2, PLA films exhibited a linear sorption behaviour with pressure, but the physical modifications induced by high pressure did not affect its use for food packaging. However, when exposed to moisture in both liquid and vapour state (i.e. environments from 50 to 100 % relative humidity (RH)), PLA was significantly degraded after two months at 50 °C (accelerated test) due to hydrolysis. This chemical deterioration was evidenced by a significant decrease of the molecular weight, which consequently induced a loss of transparency and an increase of the crystallinity. The hydrolysis was accelerated when the chemical potential of water was increased, and it was surprisingly higher for vapour compared to liquid state. In addition, pH did not affect the rate of hydrolysis.Knowing much better the limitation of PLA films, the challenge was to improve its functional properties by combining them with WG, as a high gas barrier bio-sourced and biodegradable polymer. The use of high pressure homogenization produced homogeneous WG coatings, with improved performances. This process was thus selected for making 3 layer complexes by assembly of a wheat gluten layer between two layers of PLA, together with corona treatment and hot press technologies.Corona treatment applied to PLA physically and chemically modified its surface at the nanometer scale (...)
I materiali plastici convenzionali trovano impiego in tutti campi della nostra vita, specialmente nel settore del packaging alimentare, ed in seguito all’utilizzo contaminano e danneggiano il nostro ecosistema. Materiali plastici derivanti da risorse naturali e biodegradabili, come acido polilattico (PLA), sono attualmente disponibili sul mercato anche se caratterizzati da performances inferiori.Questo progetto di dottorato è mirato 1) allo studio della stabilità di film di PLA a varie condizioni di stoccaggio come temperatura, umidità relativa, pH, o esposizione a vapori o gas; 2) a comprendere meglio le influenze di alcuni processi industriali come trattamento corona e hot press nelle proprietà dei film di PLA; 3) a sviluppare complessi multistrato tra film di PLA e di glutine che abbiano proprietà barriera più elevate rispetto ai singoli film.Gli imballaggi a base di PLA sono stati prodotti da Taghleef Industries, produttore leader nel settore e dotato di infrastrutture atte ai trattamenti di modificazione di superfice come il trattamento corona. I film a base di glutine e i coatings sono stati sviluppati e ottimizzati su scala di laboratorio, così come i complessi trilaminari PLA-glutine-PLA.Le proprietà fisiche e chimiche dei film di PLA sono state investigate a livello di superficie, così come a livello di bulk. Diverse tecniche analitiche, provenienti dal campo delle scienze dei materiali e delle scienze degli alimenti, sono state adottate in questo progetto di dottorato come calorimetria differenziale a scansione (DSC), termogravimetria (TGA), cromatografia di esclusione molecolare (SEC), microscopia a forza atomica (AFM), microscopia elettronica a scansione (SEM), spettrofotometria infrarossa a trasformata di Fourier in riflettanza totale attenuata (ATR-FTIR) e spettroscopia fotoelettronica a raggi X (XPS).Le proprietà funzionali come le permeabilità al vapore acqueo (H2O), all’ossigeno (O2), al diossido di carbonio (CO2) o all’elio (He) sono state investigate, cosi come l’assorbimento di gas e/o vapori, le proprietà meccaniche e le proprietà di superfice.Nonostante i film di PLA assorbano linearmente CO2 a pressioni crescenti, l’assorbimento di tale gas è ridotto a basse pressioni in modo da non modificare le sue proprietà fisiche – come contrariamente osservato quando il PLA è esposto a CO2 ad alte pressioni – e da non influenzare negativamente il suo utilizzo come imballaggio alimentare. Ad ogni modo, quando i film di PLA sono esposti ad ambienti umidi, o quando sono immersi in acqua liquida, sono significativamente degradati per idrolisi dopo due mesi di stoccaggio a 50 °C (test accelerato). Questo deterioramento chimico è stato evidenziato da una significativa riduzione del peso molecolare del PLA che, conseguentemente, induce una sua perdita di trasparenza e ne incrementa la sua cristallinità. Inoltre, è stato evidenziato che il pH non influenza la velocità di idrolisi. Quest’informazione ha importanza pratica per possibili utilizzi di PLA come imballaggio di alimenti ad alta umidità.Il glutine è stato scelto per le sue alte proprietà barriera, quando è protetto da ambienti ad alta umidità. Si è visto che l’incorporazione di lipidi non porta con sé grandi miglioramenti nelle performances dei film a base di glutine. Invece, l’utilizzo della tecnologia di omogeneizzazione ad alte pressioni permette una migliore dispersione del glutine, ottenendo film più omogenei e con migliori proprietà funzionali. Questa tecnologia è stata quindi scelta per produrre i complessi multistrato, intercalando i film di glutine tra due film di PLA, usando il trattamento hot press (10 MPa, 130 °C, 10 min). Si è osservato che il trattamento hot press modifica le proprietà dei film di PLA, di glutine e dei film multistrato Hot press induce cristallizzazione in PLA, e conseguentemente aumenta le sue proprietà barriera complessive, approssimativamente al 40 % all’acqua e al 60 % all’ossigeno (...)
Los materiales plásticos tradicionales son utilizados en todos los campos de nuestra vida y en particular modo como embajales de productos alimenticios; los cuales después de ser utilizados contaminan y dañan nuesto medio ambiente. Materiales plásticos derivados de recursos naturales y biodegradables, como el ácido poliláctico (PLA) se encuentran actualmente disponibles en el mercado a pesar de sus menores performances. Este proyecto de doctorado está orientado 1) al estudio de la estabilidad de películas de PLA bajo diferentes condiciones como temperatura, humedad relativa, pH o exposición a vapores o gases, 2) comprender los efectos en las propiedades de las películas de PLA de algunos procesos industriales como el tratamiento corona y hot press, 3) desarrollar complejos multicapas de PLA y gluten que tengan propiedades barrera mejores que las de las películas individuales.Los embalajes a base de PLA han sido producidos por Taghleef Industries, productor líder en el sector y dotado de las infraestructuras industriales adaptadas a los tratamientos superficiales como el tratamiento corona. Las películas de gluten y los coatings han sido desarrollados a escala de laboratorio, así como los complejos tricapa PLA-gluten-PLA.Las propiedades físicas y químicas de las películas de PLA han sido investigadas a nivel de superficie así como a nivel de bulk. Diferentes técnicas de análisis, frecuentemente utilizadas en los campos de las ciencias de los materiales y de las ciencias de los alimentos, han sido empleadas en este proyecto como calorimetría diferencial de barrido (DSC), análisis termogravimétrico (TGA), cromotagrafía de exclusión por tamaño (SEC), microscopía de fuerza atómica (AFM), microscopía electrónica de barrido (SEM), espectroscopía de infrarrojos por transformada de Fourier con reflectancia total atenuada (ATR-FTIR) y espectroscopía fotoelectrónica de rayos X (XPS).Las propiedades funcionales de los embalajes como las permeabilidades al vapor de agua, al oxígeno (O2), al dióxido de carbono (CO2) o al helio (He) han sido investigadas, asi como la absorción de gases/vapores, las propiedades mecánicas y las propiedades superficiales. A pesar de que las películas de PLA absorven linealmente CO2 a presiones mayores, la absorción del gas es reducida a bajas presiones y no modifica las propiedades físicas del PLA, como contrariamente sucede cuando el PLA es expuesto a altas presiones de CO2. Por lo tanto, su influencia en las propiedades funcionales del PLA es mínima en las normales aplicaciones alimentarias. De todos modos cuando los embalajes de PLA son expuestos a ambientes húmedos o cuando son sumergidos en agua, procesos de hidrólisis los degradan significativamente después de dos meses de conservación a 50 °C (test acelerado). Este deterioramiento químico ha sido evidenciado por una significativa reducción del peso molecular del PLA, que en consecuencia induce una pérdida de transparencia y un aumento de su cristalinidad. Además, se ha observado que el pH no influye en la velocidad de hidrólisis. Esta información tiene una importancia práctica para posibles usos del PLA como embalajes de alimentos a alta humedad. El gluten ha sido elegido por sus altas propiedades barrera cuando es protegido de ambientes a alta humedad. La incorporación de lípidos en las películas de gluten no han mejorado sus performances. Pero la tecnología de la homogenización a altas presiones ha permitido mejorar la dispersión del gluten, obteniendo películas más homogéneas y con mejores propiedades funcionales. Esta tecnología ha sido, por lo tanto, elegida para producir los complejos multicapa, intercalando las películas de gluten entre dos de PLA, utilizando el tratamiendo hot press (10 MPa, 130 °C, 10 min) (...)

[EN] In the present Doctoral Thesis, antimicrobial active packaging materials, at lab and at semi-industrial scale, have been developed with the aim to reduce the natural flora of peeled and cut fruit and extend its shelf life. Packaging prototypes have been developed for their further application. Prior to developing the active materials, the most suitable active agents were selected. To that end, the antimicrobial properties of the volatile active agents citral, hexanal and linalool and mixtures thereof were evaluated against typical microorganisms related to fruit spoilage, molds and yeast, concluding that the effectiveness of the mixture is higher than the sum of the effectiveness of the individual agents. Likewise, non-volatile antimicrobial agents such as potassium sorbate and sodium benzoate were selected, which are widely used in the food industry due to their antifungal properties. With the selected active agents, monolayer polypropylene (PP) films with different concentration of the active mixture citral, hexanal and linalool, at lab scale by means of extrusion, and bilayer films at semi-industrial scale with different active layer thickness by means of coextrusion were prepared. Besides, active packaging trays were developed at semi-industrial scale by thermoforming active sheets obtained by coextrusion of PP and ethyl vinyl acetate (EVA) compounds containing potassium sorbate and sodium benzoate as active agents. Mechanical, barrier and thermal properties of the developed active packaging materials, as well as their sealability and transparency were evaluated. In general, the materials' properties were not affected in a significant manner. However, active trays decreased in transparency due to the incorporation of non-volatile active agents. The release kinetics of the volatile and non-volatile active agents were studied at different temperatures, defining their diffusion coefficients by the adjustment to mathematic models based on Second's Law Fick. Among the volatile active agents, hexanal showed a higher diffusion coefficient, followed by citral and linalool. On the other hand, very small differences were observed between potassium sorbate and sodium benzoate diffusion coefficients, being of the same order of magnitude. In vitro tests were also performed at different temperatures to evaluate the antimicrobial properties of the developed materials. In general, the active packaging materials showed high antimicrobial properties which were enhanced with the increment of temperature. Once the properties of the developed materials were evaluated, in vivo tests with peeled and cut orange and pineapple were performed by packing these fruits with the active film, active tray and their combination (active packaging system). In general, the active packaging system improved the microbiological preservation of the fruit for longer times, between 2 and 7 days for orange and pineapple, respectively, and maintained quality parameters of the fruit at stable levels for longer times. Lastly, the safety of the active packaging materials was evaluated according to the European food contact materials and food legislation, and it was concluded that these materials were not of any safety concern for the consumers.
[ES] En la presente Tesis Doctoral se han desarrollado materiales de envase activo antimicrobiano, a escala laboratorio y a escala semi-industrial, con el objetivo de reducir la proliferación de la flora natural de la fruta pelada y cortada y extender su vida útil. Se han desarrollo distintos prototipos para su posterior aplicación industrial Previo al desarrollo de los materiales de envase, se ha realizado una selección de agentes activos más idóneos. Para ello se han estudiado mediante ensayos in vitro las propiedades antimicrobianas de agentes activos volátiles, citral, hexanal y linalool y diferentes mezclas de los mismos, frente a distintos microorganismos típicos del deterioro de las frutas, mohos y levaduras, concluyendo que la efectividad de la mezcla de los tres es superior a la suma de la efectividad de los activos de forma individual. Así mismo, también se han seleccionado antimicrobianos no volátiles como el sorbato potásico y benzoato sódico, los cuáles son ampliamente empleados en la industria alimentaria debido principalmente a sus propiedades antifúngicas. Con los agentes activos seleccionados, se han desarrollado películas monocapa de polipropileno (PP) con distintas concentraciones de la mezcla activa, citral, hexanal y linalool, a escala laboratorio, mediante técnicas de extrusión, y películas bicapa a escala semi-industrial con distintos espesores de capa activa mediante coextrusión. Por otra parte, se desarrollaron bandejas activas a escala semi-industrial mediante termoconformado de láminas obtenidas por coextrusión de compuestos de PP y etilvinilaceteto (EVA) con sorbato potásico o benzoato sódico como agentes antimicrobianos. Se han evaluado las propiedades mecánicas, barrera y térmicas de los materiales activos desarrollados, así como su sellabilidad y transparencia. En general, las propiedades de los polímeros no se vieron afectadas de manera relevante. Sin embargo, las bandejas activas perdieron su carácter transparente debido a la incorporación de los agentes activos no volátiles. Se ha estudiado la cinética de liberación de los compuestos activos volátiles y no volátiles a distintas temperaturas, determinando los coeficientes de difusión de los agentes activos mediante el ajuste a modelos matemáticos de difusión basados en la Segunda Ley de Fick. Entre los agentes volátiles, el hexanal mostró un mayor coeficiente de difusión seguido de citral y linalool. Por otra parte, no hubo apenas diferencia en los coeficientes de difusión del sorbato potásico y benzoato sódico, siendo éstos del mismo orden de magnitud. Igualmente, se han realizado diferentes experimentos in vitro a distintas temperaturas para determinar las propiedades antimicrobianas de los materiales desarrollados. En general, los materiales activos presentan una elevada capacidad antimicrobiana que se ve potenciada al aumentar la temperatura de exposición. Una vez evaluadas las características de los materiales desarrollados, se han efectuado ensayos de envasado de naranja y piña pelada y cortada con las películas y las bandejas activas y con la combinación del sistema de envase bandeja activa termosellada con la película activa. En general, el sistema de envase activo mejoró la conservación de la fruta por un mayor tiempo, entre 2 y 7 días para la naranja y piña, respectivamente, presentando una gran capacidad antimicrobiana y manteniendo los parámetros de calidad de la fruta en niveles estables por un mayor tiempo. Por último, se ha estudiado la seguridad de estos materiales de acuerdo a la legislación de materiales en contacto con alimentos y la legislación alimentaria europea, concluyendo que los materiales activos desarrollados no presentan preocupación para la seguridad de los consumidores.
[CAT] En la present Tesi Doctoral s'han desenvolupat materials d'envasament actiu antimicrobià, a escala de laboratori i a escala semi-industrial amb l'objectiu de reduir la proliferació de la flora natural de la fruita pelada i tallada i estendre la seua vida útil. S'han desenvolupament diferents prototips per a la seua posterior aplicació industrial. Previ al desenvolupament dels materials actius, s'han seleccionat els agents actius mes idonis estudiant mitjançant assajos in vitro les propietats antimicrobianes d'agents actius volàtils, citral, hexanal i linalool i diferents mescles dels mateixos, enfront de diferents microorganismes típics de la deterioració de les fruites -floridures i llevats- concloent que l'efectivitat de la mescla dels tres és superior a la suma de l'efectivitat dels actius de forma individual. Així mateix, s'han seleccionat antimicrobians no volàtils, sorbat potàssic i benzoat sòdic, els quals son àmpliament empleats a l'industria alimentaria per les seues propietats antifúngiques. Amb els agents actius seleccionats, s'han desenvolupat pel·lícules monocapa de polipropilè (PP) amb diferents concentracions de la mescla activa, citral, hexanal i linalool, a escala laboratori, mitjançant tècniques d'extrusió, i pel·lícules bicapa a escala semi-industrial amb diferents espessors de capa activa mitjançant coextrusió. D'altra banda, s'han desenvolupat safates actives a escala semi-industrial mitjançant termoconformació de làmines obtingudes per coextrusió de compostos de PP i etil vinil acetat (EVA) amb sorbat potàssic o benzoat sòdic com a agents antimicrobians. S'han avaluat les propietats mecàniques, barrera i tèrmiques dels materials actius desenvolupats, així com la seua sellabilidad i transparència. En general, les propietats dels polímers no es van veure afectades de manera rellevant. No obstant això, les safates actives van perdre el seu caràcter transparent a causa de la incorporació dels agents actius no volàtils. S'ha estudiat la cinètica d'alliberament dels compostos actius volàtils i no volàtils a diferents temperatures, determinant els coeficients de difusió dels agents actius mitjançant l'ajust a models matemàtics de difusió basats en la Segona Llei de Fick. Entre els agents volàtils, l' hexanal va mostrar un major coeficient de difusió seguit de citral i linalool. D'altra banda, no va haver-hi a penes diferències en els coeficients de difusió del sorbat potàssic i benzoat sòdic, sent aquests del mateix ordre de magnitud. Igualment, s'han realitzat diferents experiments in vitro a diferents temperatures per determinar les propietats antimicrobianes dels materials desenvolupats. En general, els materials actius presenten una elevada capacitat antimicrobiana que es veu potenciada en augmentar la temperatura d'exposició. Una vegada avaluades les característiques dels materials desenvolupats s'han efectuat assajos d'envasament de taronja i pinya pelada i tallada amb la safata, la pel·lícula activa i la seva combinació (sistema d'envàs actiu). En general, el sistema d'envàs actiu va millorar la conservació de la fruita per un major temps, entre 2 i 7 dies per a la taronja i pinya respectivament, presentant una gran capacitat antimicrobiana i mantenint els paràmetres de qualitat de la fruita en nivells estables per un major temps. Finalment, s'ha estudiat la seguretat d'aquests materials d'acord a la legislació de materials en contacte amb aliments i la legislació alimentària europea, concloent que els materials actius desenvolupats no presenten preocupació per a la seguretat dels consumidors.
Lara Lledó, MI. (2016). Antimicrobial packaging system for minimally processed fruit [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61388
TESIS
Premiado

Oggi frutta e verdura sono trasportate e distribuite sul mercato in imballaggi chiusi con film plastici o bio. La confezione assicura una migliore protezione del prodotto contro gli impatti meccanici e climatici, permettendo di prolungare la loro shelf-life. A questo fine e' fondamentale conoscere le proprieta' di barriera presentate dai film nei confronti di ossigeno, anidride carbonica e vapore acqueo. Scopo del mio lavoro di tesi e' stato quello di ricercare un nuovo e diverso metodo, alternativo ai tradizionali citati in letteratura e basati per lo piu' sull'impiego di costose attrezzature tipo gas cromatografi, per la determinazione e il calcolo del coefficiente di permeabilita' ai gas e al vapore acqueo di film plastici e biodegradabili usati per il confezionamento di frutta e vegetali freschi/freschissimi senza l'impiego della MAP (atmosfera modificata). Le prove sono state condotte mediante l'utilizzo di una strumentazione a basso costo appositamente realizzata in laboratorio e consistente in due cilindri di plexiglas recanti all'interno due box di plastica contenenti frutti climaterici e coperti con i film oggetto di studio (2 plastici e due biodegradabili). Sia i cilindri sia i box erano equipaggiati con un kit di sensori collegati a data logger per misurare i valori di concentrazione dell'ossigeno e dell'anidride carbonica, l'umidita' relativa e la temperatura con tempo di campionamento di 2 minuti. Questa struttura cosi' organizzata era inserita all'interno di una camera termica in maniera tale da poter controllare e regolare opportunamente i valori di temperatura. Si sono simulate due condizioni di temperatura, corrispondenti a due differenti condizioni di stoccaggio: temperatura progressivamente crescente da circa 0 a circa 25à à °C e temperatura fluttuante da circa 0 a circa 10à à °C. Il principio di misura applicato sfrutta la variazione naturale della composizione dell'atmosfera all'interno delle confezioni conseguente alla normale attivita' respiratoria della frutta. Misurando la variazione nel tempo della concentrazione dei gas chiave (anidride carbonica, ossigeno, vapor d'acqua) nei due ambienti (cilindro e box) separati dal film oggetto di studio, si e' messa a punto una procedura che consente di pervenire alla determinazione della permeabilita' del film ai gas considerati. Tutta la procedura di calcolo e' stata basata sull'equazione di stato dei gas perfetti e sulle leggi della psicrometria dell'aria umida. Tutte le fasi preliminari di trattamento dei segnali e tutte le equazioni per il calcolo delle quantita' di interesse sono state implementate utilizzando il linguaggio di programmazione del software open source R. I risultati hanno permesso di testare la validita' del metodo proposto, nel senso che hanno condotto alla determinazione di coefficienti di permeabilita' all'anidride carbonica, all'ossigeno e al vapore acqueo comparabili con quelli riscontrati in letteratura per film simili a quelli utilizzati (film per la conservazione di frutta fresca). Inoltre, i risultati hanno confermato pure gli aspetti teorici del modello diffusionale circa la tendenza crescente della permeabilita' al crescere della temperatura. Infine, sulla base delle leggi della psicrometria, le prove hanno permesso di evidenziare che le fluttuazioni di temperatura possono portare alla formazione di condensa sulla superficie dei film, con possibile deterioramento dell'alimento e quindi riduzione della sua shelf-life. Il lavoro svolto e' da considerarsi solamente un primo approccio, certamente suscettibile di ulteriori sviluppi futuri. Esso ha sostanzialmente dimostrato la validita' della metodologia proposta, che puo' essere perfezionata in modo da pervenire a determinazioni piu' precise ed accurate. A tal fine: Si potrebbero utilizzare sensori di ossigeno e anidride carbonica caratterizzati da un range di misura piu' ampio, cosi' da permettere l'esecuzione di prove di durata maggiore. Si potrebbero utilizzare data logger con una risoluzione piu' elevata, cosi' da agevolare o addirittura da rendere superflue le operazioni di pre-trattamento dei segnali. Si potrebbero aggiungere sensori di pressione, per tenere conto delle effettive variazioni di tale grandezza sia per cambiamenti nelle condizioni barometriche ambientali sia perche' indotte dalle variazioni di temperatura. Ancora, si potrebbe approfondire l'analisi dei dati, provando a modellizzare anche le fasi di assorbimento e desorbimento del gas o vapore, cosi' da valutare le caratteristiche dei film anche durante i transitori. Infine, per approfondire le problematiche legate alla formazione di condensa, si potrebbe studiare l'influenza esercitata sul coefficiente di permeabilita' da diversi tipi assorbitori di umidita' da includere all'interno delle confezioni.

Bakgrund: Trots plastfilmen negativa miljöpåverkan används den idag i hög utsträckning som förpackningsmaterial vid lastsäkring, detta då plastens materialegenskaper överträffar andra konkurrerade material. Plastfilm är ett förbrukningsmaterial, vilket gör att det inte kan återanvändas och stora mängder avfall skapas. Trots vetskapen om plastavfallets negativa påverkan på miljön läggs tonvikten på den ekonomiska aspekten när förpackningsmaterial diskuteras, medans miljön utlämnas eller har mindre fokus. Syfte: Studiens syfte är att utifrån identifierade faktorer utvärdera alternativa lastsäkringsmetoder som leder till en minskad användning av plastfilm utan att äventyra kvalitén på livsmedelsvaror under transport. Frågeställningar: (1) Vilka faktorer påverkar val av lastsäkringsmetod vid samlastade livsmedel? (2) Vilka alternativa lastsäkringsmetoder kan vidtas för att minska användningen av plastfilm i lastsäkringsprocessen? Genomförande: Denna studie motsvarar en enfallsstudie som är utförd hos Martin & Servera. Empiri insamling har främst skett via semi-strukturerade intervjuer och direkta observationer. I och med Covid-19 har även strukturerade intervjuer behövs genomföras. Utifrån observationer och intervjuer har en kartläggning av Martin & Serveras utgående logistik samt lastsäkringsprocess skett för att finna faktorer som påverkar valet av lastsäkringsmetod. Faktorerna har stått till grund vid framtagning av utvärderingskriterier, som har använts för att utvärdera alternativa lastsäkringsmetoder. De alternativa metoderna är funna genom intervjuer. Resultat: Totalt identifierades sju faktorer som påverkar val av lastsäkring metod: förpackningsformer, typ av lagersystem, lagerarbetare, krav/lagar/regleringar, typ av lastbärare, omslagsmaterialets egenskaper samt vilket typ av produkt som hanteras. Utifrån faktorerna framställdes utvärderingskriterier som sedan applicerades på fyra alternativa lastsäkringsmetoder (Plastskiva, Add-On Door Flex, 2 Kompletterande Dörrar samt Bioplastfilm). Samtliga metoder bidrog till minskad användning av plastfilm. Utifrån utvärderingskriterierna; Skydd & Stabilitet, Krav/Lagar/Reglering, Kostnad, Tidsåtgång, Miljö rekommenderas plastskivan som första alternativa lastsäkringsmetoden till plastfilm.

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

Inspiré par la technique couche par couche traditionnelle (LBL), Ce travail de thèse démontre le premier effort pour développer une nouvelle méthodologie pour l’auto-assemblage des multicouches sur la base des interactions hydrophobes et d'adsorption physique pour fabriquer des films composites stratifié en Polyéthylène (LLDPE) - organoargile (OMMT). Contrairement à la technique LbL électrostatique, ici, les films multicouches ont été synthétisés en partant d'un substrat de polymère non polaire/non chargé et successivement le dépôt de couches d’organo-argile apolaire et de couches de PE non polaires/non chargés avec des dépôts répétitifs qui se suivent. La variation alternative de l'angle de contact (85° en moyenne pour l’organo-argile et 107° pour les couches de PE) a confirmé la profilométrie et les résultats de la microscopie électronique à balayage, ainsi que le modèle de croissance linéaire, la formation très stratifiée réussie de bicouches répétitives composées de 450 nm couches d’organo-argiles et 2,25 µm couches de PE. Ultérieurs essais de caractérisation ont été effectués pour évaluer l'effet de la variation des principaux paramètres de processus identifiés (concentration, température, les étapes de rinçage et de séchage, et le type de solvant), sur la formation et la croissance d'épaisseur des films. En conséquence, la forte dépendance de l'auto-assemblage aux paramètres du procédé testés a été montrée par les résultats expérimentaux obtenus. Les propriétés de barrière des films multicouches ont également été évaluées par la caractérisation de la perméabilité à la vapeur d'eau, à l'oxygène (O2) et au dioxyde de carbone (CO2), ainsi que la sorption de la vapeur d'eau. Un revêtement de 5 bicouches (OMMT/PE) (~ 14 µm d'épaisseur) a réduit la perméabilité à l'O2 d'un film de PE de 160 µm d'épaisseur de 84,4% et la perméabilité au CO2 de 70%, tandis que la perméabilité a la vapeur d’eau a été réduite de 45%. Ces réductions de perméabilité obtenues par seulement l’ajout de 2,4% (v/v) de nano-argile se sont révélés être significativement plus élevée par rapport aux valeurs de réduction rapportées dans la littérature pour les nanocomposites dispersés préparés à base de PE/organo-argile. Cette connaissance peut être utilisée dans la mise en place d'une approche pour produire des micro/nanostructures stratifiés ayant des propriétés de barrière sur mesure pour l'application dans l'emballage alimentaire
Inspired by the traditional Layer-by-Layer (LbL) assembly technique, this PhD study demonstrates the first effort to develop a novel methodology for multilayer self-assembly on the basis of hydrophobic interactions and further physical adsorption to fabricate stratified Polyethylene(LLDPE)-organoclay(OMMT) nano-enabled composite film. In contrary to the electrostatic LbL technique, here, the multilayer films were synthesized by starting from an uncharged apolar polymer substrate and successively depositing apolar organoclay and uncharged apolar PE layers with subsequent repeating depositions. The alternate variation of contact angle (85° average for organoclay and 107° for PE layers) confirmed the profilometry and the scanning electron microscopy results as well as the linear growth pattern, i.e. the successful highly stratified assembly of repetitive bilayers comprised of 450 nm organoclays and 2.25 µm PE layers. Further characterization tests were performed to evaluate the effect of the main identified process parameters (concentration, temperature, rinsing and drying steps, and solvent type) variation on the formation and thickness growth of the films. As a consequence, the high dependence of the self-assembly’s growth to the tested process parameters was showed by the obtained experimental results. The barrier properties of the multilayer films were also evaluated by characterizing the Water vapour, Oxygen (O2), and Carbon dioxide (CO2) permeability as well as the water vapour sorption. A 5-bilayer (OMMT/PE) coating (∼14 µm thick) reduced the O2 permeability of a 160 µm-thick PE film by 84.4% and the CO2 permeability by 70%, while the WVP was reduced by 45%. These permeability reductions obtained by only 2.4 v/v % of nanoclay addition level were found to be significantly greater compared to the reduction values reported in the literature for prepared blend PE/organoclay nanocomposites. This knowledge can be used in the establishment of an approach to produce stratified micro/nanostructures with tailored barrier properties for food packaging application

The packaging industry is highly dependent on fossil resources and have serious environmental drawbacks. The largest part of the total volume of plastic waste is generated from food packaging, so new packaging strategies with green materials are required. Using the edible packaging films which are renewable, biodegradable and versatile, can reduce the amount of plastic waste. Also, there is an increasing demand of higher quality foods and a growing interest from consumers for minimally processed fresh-like foods with an extended shelf life. Edible films can be effective barriers which prevent unwanted mass transfers in foods. They can be green alternative to synthetic petroleum-based polymer packaging materials and nowadays this topic is a fast-growing area. Sodium alginate as a natural polysaccharide can be used for edible films with excellent properties such as transparency. But, sodium alginate practical applications in food packaging are limited as single-component because of poor mechanical and barrier properties. At the same time, pullulan is an extracellular and water-soluble microbial polysaccharide with good film-formation properties. The packaging materials made from pullulan and alginate may be better candidates for edible packaging films. The objective of this study was to formulate pullulan and sodium alginate based edible films for food packaging. For that purpose a series of pullulan/alginate films with different ratios were prepared. To improve film flexibility and processability, glycerol was added as plasticizers in the film formulation. Designed films were solvent cast from aqueous polymer solution. Understanding the film-forming mechanism during the drying process is crucial to predict properties of the obtained films, so rheological properties of prepared solutions were investigated. Formulated films have the potential to be used as inner primary packaging and can be manufactured by preparing a film-forming composition and enclosing a food product with the film. Using this kind of packaging material, no waste is generated contributing to the circular economy.

The shelf life of foods is mostly limited by microbial growth and oxidation reactions. Reducing both these mechanisms by active packaging is an attractive concept to enhance the shelf life. Antimicrobial packages recently developed combine natural antimicrobial compounds like carvacrol and isothiocyanates with biobased polylactic acid (PLA) films. Antioxidant packaging can be used to further improve product quality and extend the shelf life of food by free radical scavenging. As an example, a radical scavenger and singlet oxygen quencher, b-carotene, was incorporated into PLA to develop an antioxidant film. The usage of sunflower oil based oleogel as lipid food model was chosen to focus on the lipid oxidation process. We studied the antioxidant activity and color/thermal properties of the antioxidant loaded PLA film. Preliminary results show that the thermal stability of films was not affected by b-carotene addition. b-carotene significantly improved the antioxidant properties of the films in both DPPH and ABTS radical-scavenging activity tests. We evaluated the oxidation stability of sunflower oil based oleogels as a model food product prepared with different proportions of stearic acid (SA) and hydroxypropyl methylcellulose (HPMC). The difference between direct and indirect contact between the product and the film was determined. Preliminary results show that b-carotene-loaded PLA film was able to inhibit lipid oxidation, reducing the formation of lipid hydroperoxides and TBARS of the resulting oleogels. Further research will be on combining the antioxidant and antimicrobial activity of packaging films to further enhance the shelf life of products vulnerable to oxidation and microbial spoilage.

We live in a world that usually use plastic bags either to go shopping or to pack the snack for a short trip. However, packaging makes life easier and serves as protection for products such as food. Bread is a common food product that needs packaging in order to be protected at storage and transportation. Therefore, with aim of reducing petroleum derived packagin g consumption it was developed an edible film from potato starch to packeg bread and some quality characteristics like water content, firmness and weight loss were evaluated, showing that edible film can be used as a packaging.Keywords: biopolymers; edible coatings; packaging materials; starch; storage.

Changes in consumer preferences in order to reach safe food have led to innovations in packaging technologies. Intelligent and active packaging is a constantly developed packaging technology that plans to offer safer and higher quality products. Active packaging refers to the inclusion of additives in the package in order to maintain and / or extend shelf life and product quality. Intelligent systems, on the other hand, are systems that monitor the status of packaged food during this entire period to provide information about the quality of the packaged during storage and transportation. The aim of this study is to produce a completely natural intelligent packaging material using rosehip extract and biopolymer, which is a substance that naturally changes color with pH. In this study, cellulose acetate butyrate biobased films containing different rates (1, 2.5, 5, 10 wt%) of rosehip extract were produced by solvent casting method. The chemical structure the rosehip containing biobased film and blank biobased film were characterized by ATR-FTIR. The transparency of prepared five different films were determined by UV spectroscopy. The color characteristic of blank and rosehip containing films measured with spectrophotometer. Surface energy of all films and contact angles were determined with goniometer. Biobased films were printed and printability parameters such as color, gloss, contact angle, surface tension were examined. It is concluded that blank biobased film is colorless, transparent and all biobased films have good printability. It was determined that the amount of rosehip extract increased the color change visibly. The biobased films obtained are pink in acidic medium and yellow-green in alkaline medium. The results prove that biobased film produced with rosehip extract and cellulose acetate butyrate can be used in intelligent packaging applications.

Fresh fruit has recently gained popularity in the market for healthy, organic, functional, and convenient foods. Production and consumption of fresh fruit increases from time to time. Consumer demand for fresh fruits that are rich in nutrition and health benefits have presented a challenge to the food industry to obtain appropriate technology to meet the need. However, there are some limitations regarding the storage of the fresh fruits. Fresh fruits cannot stand for a long term due to the rapid of ripening process in the fruit’s tissues. The ripening process commonly related to the respiration and transpiration process in the fruits tissue. Besides, the fresh-cut fruits also easily getting spoilage with a growth of microbial in the fruits. There are some innovations regarding packaging food film from synthetic materials which are quite wide applied in the food industry. This material is not an environmentally friendly due to the synthetic’s materials are not made by natural resources. Study towards the application of natural resources in the formation edible film packaging have been done. It is due to the global demand to replace the synthetic plastic film packaging with biodegradable film packaging that are environmentally friendly and users friendly. This review aims at providing a broad overview of recent scientific research related to preservation of fruits in the food industry and its health effects in consumers. It involved recent analysis of edible film incorporate with different type of essential oils from natural sources such as plants for preservations of fruits.

This work was in response to the Defense Logistic Agency’s (DLA) Subsistence Network Broad Agency Announcement, BAA-0003-16 addressing 2019 NDAA Section 329 that states packaging materials used for Meals Ready-to-Eat (MRE) that contact food products must be free of per- and polyfluoroalkyl substances (PFAS). This was addressed by determining the presence or absence of PFAS on MREs by extraction followed by gas chromatography mass spectrometry (GC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Any samples positive for PFAS were quantitated using LC triple quadrupole (QqQ) MS at the US Army Engineering and Research Development Center (ERDC) and by high resolution quadrupole time-of-flight (qTOF) MS and GC-MS at Oregon State University (OSU).