Dissertations / Theses on the topic 'Food packaging systems'

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.

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.

The expanding role of electronic nose instrumentation, as a quality-monitoring tool for food-packaging materials, is examined and reviewed. The food industry is interested in determining the applicability of using an electronic nose for odor analysis of retained printing solvent levels in packaging. Three electronic nose systems were optimized for this application and their performance assessed. These include the FOX 3000, the Cyranose 320, and the QMB6. Response surface methodology was used to generate 2nd order models of sensor response as a function of system and experimental parameters for the three electronic nose systems. Forty-seven of 50 sensor models generated were found to be significant at an a-level of 0.05. Optimum settings, that allowed adequate signals to be obtained for the full range of examined retained solvents levels, were selected for the remaining work using these models. Performance analyses of these systems, which use three leading sensor technologies, showed that the conducting polymer sensor technology demonstrated the most discriminatory power. All three technologies proved able to discriminate among different levels of retained solvents. Each complete electronic nose system was also able to discriminate between assorted packaging having either conforming or non-conforming levels of retained solvents. Each system correctly identified 100% of unknown samples. Sensor technology had a greater effect on performance than the number of sensors used. Based on discriminatory power and practical features, the FOX 3000 and the Cyranose 320 were superior. The results indicate that electronic nose instrumentation can be used as a complimentary discriminatory tool in quality control.
Master of Science

Master of Science
Department of Food Science
Elizabeth A. E. Boyle
To validate how packaging and storage reduces Listeria monocytogenes (Lm) on whole muscle turkey jerky and smoked sausage sticks, four packaging systems, including heat seal (HS), heat seal with oxygen scavenger (HSOS), nitrogen flushed with oxygen scavenger (NFOS), and vacuum (VAC), and four ambient temperature storage times were evaluated. Commercially available whole turkey jerky and pork and beef smoked sausage sticks were inoculated with Lm using a dipping or hand-massaging method, respectively. There was no interaction on packaging and storage time on Lm reduction on smoked sausage sticks and an Lm log reduction of >2.0 log CFU/cm[superscript]2 was achieved in smoked sausage sticks packaged in HS, HSOS, and VAC. A >2.0 log CFU/cm[superscript]2 reduction was achieved after 24 h of ambient temperature storage, regardless of package type. NFOS was less effective in reducing Lm by more than 0.5 log CFU/cm[superscript]2 compared to HS, HSOS or VAC. After 30 d of ambient storage, Lm had been reduced by 3.3 log CFU/cm[superscript]2 for all packaging environments. In turkey jerky, Lm reduction was affected by the interaction of packaging and storage time. HS, HSOS, NFOS, or VAC in combination with 24, 48, or 72 h ambient temperature storage achieved <1.0 log CFU/cm[superscript]2. After 30 d at ambient temperature storage, Lm was reduced by >2.0 log CFU/cm[superscript]2 in HS and VAC, and could serve as a post-lethality treatment. Alternatively, processors could package turkey jerky in HSOS or NFOS in combination with 30 d ambient storage period as an antimicrobial process. Very little data has been published describing how packaging atmospheres affects Lm survival in RTE meat. The mechanism for Lm reduction under these conditions is not fully understood and additional research is needed.

This study investigated the influence of dietary antioxidants and quality of oil on the oxidative and enzymatic properties of chicken broiler meat stored in an oxygen-enriched package (HiOx: 80% O2/20% CO2) in comparison with air-permeable polyvinylchloride (PVC) or skin (SK) packaging systems during retail display 2–4 °C for up to 14, 7, and 21 d, respectively. Broilers were fed a diet either with a low-oxidized oil (peroxide vale POV 23 meq O2/kg) or with a high-oxidized oil (POV 121 meq O2/kg), supplemented with an antioxidant pack (200 ppm EconomasE and organic minerals Se, Zn, Cu, Mn, and Fe as in Bioplex) in substitution for vitamin E and inorganic minerals for 42 d. In all packaging systems, lipid oxidation and protein oxidation were inhibited by up to 65% with an antioxidant-supplemented diet when compared to diets without antioxidant supplements. Antioxidant enzyme activities were significantly higher (P < 0.05) in the antioxidant-supplemented diets compared with control diets, regardless of oil quality. Meat samples from the antioxidant-supplemented group, irrespective of oil quality, has less purge and cooking loss compared to control diets. In all packaging systems, meat shear force was higher (P < 0.05) for broilers fed high-oxidized diets than the low-oxidized groups. Comparison between muscle types (breast as white vs. thigh as red) showed a similar trend in muscle susceptibility to oxidized oil in the diet but greater protection of antioxidant supplements for thigh meat in both physiochemical and textural properties. Dietary regimen influenced protein expression in broiler breast meat. Three protein spots from 2-dimensional gel electrophoresis, identified by mass spectrometry as glyceraldehyde 3-phosphate dehydrogenase, creatine kinase, and heat shock protein beta-1 were over-abundant in muscle from low-oxidized diets. The differential proteomes that suggested down regulation of the genes encoding antioxidative proteins upon feeding oxidized oil may be implicated in the broiler meat quality deterioration during storage. In summary, feeding diets with poor oil quality increased the vulnerability of lipids and proteins to oxidation in broiler breast and thigh meat during refrigerated and / or frozen storage in various packaging conditions, yet these effects were alleviated upon dietary supplementation with antioxidants.

[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

Contamination of packaged foods due to micro-organisms entering through air leaks can cause serious public health issues and cost companies large amounts of money due to product recalls, consumer impact and subsequent loss of market share. The main source of contamination is leaks in packaging which allow air, moisture and microorganisms to enter the package. In the food processing and packaging industry worldwide, there is an increasing demand for cost effective state of the art inspection technologies that are capable of reliably detecting leaky seals and delivering products at six-sigma. The new technology will develop non-destructive testing technology using digital imaging and sensing combined with a differential vacuum technique to assess seal integrity of food packages on a high-speed production line. The cost of leaky packages in Australian food industries is estimated close to AUD $35 Million per year. Contamination of packaged foods due to micro-organisms entering through air leaks can cause serious public health issues and cost companies large sums of money due to product recalls, compensation claims and loss of market share. The main source of contamination is leaks in packaging which allow air, moisture and micro-organisms to enter the package. Flexible plastic packages are widely used, and are the least expensive form of retaining the quality of the product. These packets can be used to seal, and therefore maximise, the shelf life of both dry and moist products. The seals of food packages need to be airtight so that the food content is not contaminated due to contact with microorganisms that enter as a result of air leakage. Airtight seals also extend the shelf life of packaged foods, and manufacturers attempt to prevent food products with leaky seals being sold to consumers. There are many current NDT (non-destructive testing) methods of testing the seal of flexible packages best suited to random sampling, and for laboratory purposes. The three most commonly used methods are vacuum/pressure decay, bubble test, and helium leak detection. Although these methods can detect very fine leaks, they are limited by their high processing time and are not viable in a production line. Two nondestructive in-line packaging inspection machines are currently available and are discussed in the literature review. The detailed design and development of the High-Speed Sensing and Detection System (HSDS) is the fundamental requirement of this project and the future prototype and production unit. Successful laboratory testing was completed and a methodical design procedure was needed for a successful concept. The Mechanical tests confirmed the vacuum hypothesis and seal integrity with good consistent results. Electrically, the testing also provided solid results to enable the researcher to move the project forward with a certain amount of confidence. The laboratory design testing allowed the researcher to confirm theoretical assumptions before moving into the detailed design phase. Discussion on the development of the alternative concepts in both mechanical and electrical disciplines enables the researcher to make an informed decision. Each major mechanical and electrical component is detailed through the research and design process. The design procedure methodically works through the various major functions both from a mechanical and electrical perspective. It opens up alternative ideas for the major components that although are sometimes not practical in this application, show that the researcher has exhausted all engineering and functionality thoughts. Further concepts were then designed and developed for the entire HSDS unit based on previous practice and theory. In the future, it would be envisaged that both the Prototype and Production version of the HSDS would utilise standard industry available components, manufactured and distributed locally. Future research and testing of the prototype unit could result in a successful trial unit being incorporated in a working food processing production environment. Recommendations and future works are discussed, along with options in other food processing and packaging disciplines, and other areas in the non-food processing industry.

Antimicrobial (AM) films comprising of thermoplastic starch (TPS) and a commercial aliphatic polyester blended with thermoplastic starch (APTPS) were prepared and their properties, release of AM agents, and AM efficacy was studied in laboratory media and on a real foodstuff (Cheddar cheese). The AM films were prepared using two techniques: (i) direct incorporation of AM agents (carvacrol, linalool or thymol) into TPS films via a compression moulding technique; and (ii) by application of a coating containing the AM agents onto the commercial APTPS films.

Multiple studies have demonstrated atmospheric cold plasma (ACP) as an effective non-thermal technology for microbial decontamination, surface modification, and functionality alteration in food processing and packaging. ACP constitutes charged particles, such as positive and negative ions, electrons, quanta of electromagnetic radiation, and excited and non-excited molecules, which corresponds to its predominant reactive properties. However, in many of these applications, the interactions between plasma and the components in food matrix are not well-understood. The overall goals of this dissertation were to 1) evaluate the interactions between high voltage atmospheric cold plasma (HVACP) and microbes in liquid and semi-solid food; 2) investigate plasma transfer into semi-solid foods and determine the relationship between microbial inactivation and plasma transfer; 3) explore the interactions between plasma and proteins.

The first study explored the microbial (Salmonella enterica serovar Typhimurium, S. enterica) inactivation efficacy of HVACP. The physicochemical interactions between HVACP and biomolecules, including an enzyme (pectin methylesterase, PME), vitamin C and other components in orange juice (OJ) under different conditions was also evaluated. Both direct and indirect HVACP treatment of 25 mL OJ induced greater than a 5 log reduction in S. enterica following 30 s of treatment with air and MA65 gas with no storage. For 50 mL OJ, 120 s of direct HVACP treatment followed by 24 h storage achieved S. enterica reductions of 2.9 log in air and 4.7 log in MA65 gas. An indirect HVACP treatment of 120 s followed by 24 hours storage resulted in a 2.2 log reduction in air and a 3.8 log reduction in MA65. No significant (P < 0.05) Brix or pH change occurred following 120 s HVACP treatment. HVACP direct treatment reduced vitamin C content by 56% in air and PME activity by 74% in air and 82% in MA65. These results demonstrated that HVACP can significantly reduce Salmonella in OJ with minimal quality degradation.

The second study in this dissertation examined the penetration process of plasma into semi-solid food and the resulting microbial inactivation efficacy. Agar gels of various densities (0.25, 0.5, 1.0, and 2%) with a pH indicator were inoculated with S. enterica (10⁷>CFU) and exposed directly (between the electrode) or indirectly (adjacent to the plasma field created between the two electrodes) to 90 kV at 60 Hz for up to 1.5 h. A long treatment time (1.5 h) caused sample temperature to increase 5~10 °C. The microbial analysis indicated a greater than 6 log₁₀ (CFU) reduction (both with air and MA65) in the zone with a pH change. Inactivation of bioluminescence cells in the plasma penetrated zone confirmed that the plasma, and its generated reactive species, inactivate microbial as it penetrates into the gel. A two-minute HVACP direct treatment with air at 90 kV induced greater than 5 log₁₀ (CFU) S. enterica reduction in applesauce.

The third study investigated the interactions between HVACP and protein, using bovine serum albumin (BSA) as a model protein. The physicochemical and structural alteration of BSA and its reaction mechanism, when subjected to HVACP, were investigated. After treating 10 mL of BSA solution (50 mg/mL) at 90 kV for 20, 40, or 60 min, we characterized structural alteration and side-group modification. FTIR spectroscopy, Raman spectroscopy, and circular dichroism analysis indicated protein unfolding and decreased secondary structure (25 % loss of α-helix, 12% loss of β-sheet) in HVACP treated BSA. Average particle size in the protein solutions increased from 10 nm to 113 µm, with a broader distribution after 60 min HVACP treatment indicating protein aggregation. SDS-PAGE and mass spectrometer analysis observed a formation of new peptides of 1 to 10 kDa, indicating that the plasma triggered peptide bond cleavage. Chemical analysis and mass spectrometer results confirmed the plasma modifications on the side chains of amino acids. This study reveals that HVACP treatment may effectively introduce structural alteration, protein aggregation, peptide cleavage, and side-group modification to proteins in aqueous conditions, through several physicochemical interactions between plasma reactive species (reactive oxygen species and reactive nitrogen species) and the proteins. This finding can be readily applied to other plasma-protein studies or applications in the food system, such as enzyme inactivation or protein-based film modifications.

Content removed due to copyright restrictions: Smale, N.J. Tanner D.J., Amos N.D., Cleland D.J. (2003). Airflow properties of packaged horticultural produce - a practical study. Acta Horticulturae, (599), 443-450
Horticultural exports are of economic significance to New Zealand. Only through providing consistently high quality products to distant markets can New Zealand hope to command a premium price. New Zealand's two major horticultural exports, apples and kiwifruit, are transported to foreign markets by sea; either in refrigerated holds on-board cargo vessels or in refrigerated containers. Long transit times mean that conditions in these systems must be carefully controlled to ensure high quality product arrives at market. Effective distribution of air is a key consideration in transport systems. A mathematical model to describe the flow of air in marine transport systems was developed. The model was based on a resistance network framework, relying on simplification of the complex geometry within the refrigerated space to a discrete number of flow paths and points of convergence and divergence. Correlations quantifying the flow resistance of each channel were required. Some of these correlations were already available, and some were developed specifically for this purpose. A general method for predicting the flow resistance of enclosed conduits based on the Darcy-Weisbach, laminar and Colebrook equations was found to be sufficiently accurate for use. The flow resistance of horizontally vented horticultural packages was quantified and the cause of the flow resistance investigated. Entrance and exit effects were found to be significant, and a relationship between vent size and flow resistance was developed. Air interchange between a vented carton and the general refrigerated space was shown to be a significant mode of heat transfer. The effect of vent design on the rate of air interchange was found to be complex. Quantitative relationships between vent characteristics and rates of air interchange could not be developed; however, some general observations were made. Vent size, aspect ratio and alignment were all found to affect the rate of interchange. An existing method for determining in-package fluid velocities was refined to improve the accuracy of data and reduce the measurement time. A low-cost method for measuring airflows in transport systems was also developed utilising thermistors. These thermistor anemometers were used to monitor velocities in four shipments of fresh produce from New Zealand. Three of the four vessels monitored showed large variation in the circulation rate in the period between evaporator defrosts due to frosting. In some cases, frosting was severe enough to cause loss of delivery air temperature control. Management of defrosts was identified as an area of improvement in refrigerated hold management. Validation of the model developed was performed using four systems: a laboratory scale test-rig, a 40' container and two of the surveyed refrigerated holds. Airflow predictions were used with a heat transfer model to predict in-package temperatures. Comparison of measured and predicted flows and in-package temperatures showed good agreement given uncertainty of geometry and input data. The implications of altering a number of operational and design variables in both containers and refrigerated holds were investigated using the developed models. Increased circulation rates were found to increase cooling rates and reduce temperature variability in both types of systems; however, the magnitude of the benefit decreased with increasing circulation rate. Removal of the floor gratings and the use of pallet bases as an air distribution channel was found to increase temperature variability in both types of systems. The magnitude of the increase was small in a 40' container but substantial in a refrigerated hold. The correlations and models developed in this thesis provide useful tools to analyse and optimise the design and operation of refrigerated marine transport systems.

碩士
國立臺灣大學
食品科技研究所
89
ABSTRACT The objective of this thesis was to develop food packaging systems which possess both of modified atmosphere (MA) and humidity controlling (HC) functions, and are suitable for packaging foods which need to be stored at either refrigeration or room temperatures. Results showed that a MA / HC agent could be formulated with sodium ascorbate (SA), sodium carbonate-10-hydrate (SC), ferrous sulfate-7-hydrate (FS), and calcium chloride (CaCl2 ) . The calcium chloride in the formulation absorbs water vapor from the atmosphere. The absorbed water can be utilized by the other components in the formulation to initiate desired chemical reactions. When the MA / HC agents, composed of 0.3-1.3g SA, 2.6-3.6g SC, 1.6-2.8g FS, and 0.6-2.4 CaCl2, were placed in a 285 ml closed container, and allowed the reactions to proceed at 5℃ for 48 h, the oxygen and carbon dioxide contents could reach constant levels, in the ranges of 2.29 - 9.18﹪and 11.92- 28.46%, respectively, and the relative humidity maintained at 60%. A MA / HC agent was tested in the package of lettuce. The agent, composed of 0.8g SA, 3.1g SC, 2.2g FS, and 0.6g CaCl2, reduced the oxygen concentration to 1%, raised the carbon dioxide concentration to 20%; and the relative humidity was controlled at 94 ±3% for 3 days, and then increased to 100%. The lettuce packaged with MA / HA agent maintained a better color, texture, and overall acceptance than that packaged without MA / HA agent. For foods usually stored at room temperature, the developed MA / HC agents composed of SA, SC, FS, and silica gel. However, silica gel should be placed separately from the rest of the components in the packaging system. The MA agent, including SA, SC, and FS reacted to each other first to release CO2 and reduce O2 concentration in the package. Then, the silica gel could absorb water vapor to reduce the RH. When the MA / HC agents, composed of 0.3-1.3g SA, 2.6-3.6g SC, 1.6-2.8g FS, and 10g silica gel, were placed in a 285 ml closed container at 25℃for 24 hours, the oxygen and carbon dioxide contents could reach constant levels, in the ranges of 0-33.1﹪and 0-9.51, respectively, and relative humidity controlled at 10% . A MA / HC agent was tested for packaged roast peanut at room temperature. It was found that the oxygen concentration was reduced to 1%, and the carbon dioxide raised to 20%. The rate of lipid oxidation of the peanut was significantly retarded by the MA / HC agent. Although the relative humidity within the package could be reduced to approximately 20% initially, it increased gradually during storage.

碩士
大葉大學
企業管理學系碩士班
103
ABSTRACT Taiwan, during Min Guo 102 year has accumulated 409 food poisoning cases nationwide. That affected total of 3890 out of the 71 cases. 1903 patients involved in, are related to food hygiene. However 21 out of those 71 cases are related to boxed lunches, which involved 1185 people, the largest number of patients. This article focus on food safety control from boxed lunch factories, especially those delivered to primary and secondary school. Food safety has brought attention to the people in Taiwan and here we will discuss how to secure food safety on boxed lunches and to improves its quality of boxed meals. Back in 1971, the first session of the United States Conference of food preservation, quality control cannot be addressed to ensure the safety of traditional foods, the only hazard that could be potentially controlled were the manufacturing process in order to effectively improve the safety of food, which is called Hazard analysis and critical control points HACCP (Hazard Analysis and Critical Control Point) concept, which is to be discussed in the article: Lunch box food factory management. In order to implement this law, it is most suitable to let the boxed meal lunch technologist to manage the factory logistic. Thus, this explains the importance of the boxed meal lunch technologists' existence. In the early Republic of China year 74 during December 20th, the highest level of the executive branch and the Department of Health (DOH) has announced the requirement of food manufacture policy number 7. In policy number 7, it demanded food manufacture factories to have food inspectors on site. This applies to Chinese catering industries, starting from Republic of China year 88 during April 20th, all boxed meal lunches suppliers needs to follow the deployment of the food manufacturing and processing industry, foods storage spaces and facilities and food additives provision of health standards accordingly by the professional chefs who holds the legal license. In addition, during Republic of China year 91, on February 6th, the president has announced all boxed meal suppliers to schools must provide clean, healthy, and balanced nutrition lunches to students. Meanwhile, being responsible to educate and emphasize the image of healthy nutrition. Boxed meal industries require nutritionists to be on site to manage developments. Finally, the government has implemented this policy and was announced by the highest level of the executive branch and the Department of Health (DOH) during Republic of China in the year of 97 on May 8th. "One within all the professional chefs and among other nutritionists must carry legalized food handling license.” This law will take effect on Republic of China time in the year of 101 on May 8th. This law applies to high risk industries including sea foods, meat processing manufacture, boxed meal factories, milk industries. This article has studies 18 boxed meal factories in Chunghwa, Taiwan. The study also included owners of the factories, food sanitation staffs, and professional chefs, licensed nutritionists, food technicians as well as the Executive Secretary of the Board of Directors who were in charge of the boxed meal for 96 schools as the survey target. The content of the survey has concluded the all the school lunch box examinations and inspection card from the Department of Health (DOH), which was specifically designed for future inspection on boxed meal lunches. Food Safety Technician evaluated the performance and meal quality based on the eight critical control points of food safety and quality control from boxed lunches. These evaluation scores are being analyzed before and after results with SAS (Statistical Analysis System) Software. The difference of descriptive statistics including frequency and average values are being analyzed with paired t-tests. From the comparison you can find food safety technician outperformed dietitian’s management, cooking techniques, as well as food hygiene management. By promoting businesses from food industry to implement hazard analysis and critical control points system (HACCP), we shall prevent illegal food business from producing risky food products.

O objetivo desta tese é desenvolver um sistema de compra de alimentos com desperdício zero e projetar uma marca que fosse um espelho desse ADN verdadeiro. Em última instancia, esta tese espera encontrar uma solução inovadora para reduzir a quantidade de embalagens descartáveis de alimentos que se tornam resíduos ambientais prejudiciais. O Design Thinking e a investigação ativa foram as metodologias que orientaram o projeto. Entrevistas, observações de sites, e questionários foram alguns dos métodos utilizados nas fases de inovação, iteração e produção. O teste de validação utilizou uma apresentação com uma recolha de dados quantitativos e qualitativos. Os dados foram analisados e reforçaram o sucesso tanto da marca, como do sistema inovador, que oferecem uma real, e percebida, mais valia para o ambiente.
The objective of this thesis study is to develop a zero-waste system of buying food and to design a brand that reflects that honest approach. Ultimately, this thesis hopes to find a new and innovative solution to reduce the amount of one-time-use food packaging that becomes harmful environmental waste. Design thinking and action research comprised the methodologies that guided the project. Interviews, site observations, and polls were also included in innovation, iteration, and production. Validation testing utilized a presentation and survey with both quantitative and qualitative results. The data collected reinforced the success of both the brand and the innovation in offering real and perceived environmental value.

Num mercado competitivo dos dias de hoje e num clima económico incerto em que se vive, demonstrar a garantia da segurança alimentar é, cada vez mais, uma exigência para garantir a confiança dos clientes e consumidores. Assim, uma das maneiras das empresas demonstrarem aos clientes a sua capacidade em fornecer produtos e/ou serviços seguros é disporem de um sistema bem desenhado, gerido e certificado. O investimento na segurança alimentar por parte das empresas é traduzido num aumento da procura da implementação em Sistemas de Gestão da Segurança Alimentar, com a finalidade primordial na procura e superação da satisfação dos seus clientes e consumidores. Desta forma, o trabalho desenvolvido no presente relatório de estágio incidiu na realização de tarefas no âmbito da implementação de um sistema de gestão de segurança alimentar, o sistema NP EN ISO 22000:2005, realizado na empresa Unicer Bebidas, S.A, localizada em Leça do Balio. No âmbito da implementação da norma mencionada, a Unicer definiu um projeto de revisão de todas as Fichas Técnicas e Cadernos de Encargos de matérias-primas, aditivos e auxiliares e materiais de embalagem, tendo como principal objetivo a simplificação e atualização do sistema documental. Esta que viria também a ser apoiada pelos requisitos internos Unicer e pela legislação aplicável em vigor. Através desta metodologia a empresa passará a ter um sistema de regras que facilita a comunicação entre as diversas áreas da empresa, assim como com as entidades exteriores, nomeadamente com os fornecedores tornando-o também num sistema mais credível, exigente e robusto. No final, a empresa, obtêm também uma simplificação de cerca de 75% dos documentos, representando num sistema mais fiável e com melhores perspetivas de uma atualização mais eficaz.
In a competitive market of today and an uncertain economic climate we live, demonstrate ensuring food security is increasingly a requirement to ensure the trust of costumers and consumers. Thus, companies to demonstrate its customers the ability to provide products and/or safe services have an operating system, certified and well designed. The investment in food safety by companies is translated into an increase in demand for the implementation of Foods Safety Management Systems with the primary purpose in seeking and overcoming the satisfaction of its costumers and consumers. Therefore, the work described in this internship report describes the tasks performed within the implementation of a Food Safety Management System, the NP EN ISO 22000:2005 system, in the company Unicer Bebidas, S.A., located in Leça do Balio. For the implementation of this standard mentioned Unicer defined a project review of all the technical datasheets and purchasing guidelines of raw materials, additives and auxiliary and packaging materials, with the main purpose of simplifying and updating documentation system. This would also be supported by Unicer internal requirements and applicable laws in force. Through this methodology, the company will have a system of rules that makes easier the communication between the different areas of the company, as well as with external entities, particularly with suppliers translating into a more credible, demanding and robust system. In the end, the company also obtained a simplification of about 75% of the documents, representing a more reliable system and with better prospects of a more effective updating.

Purchasing food in bulk has become a growing practise among grocery shoppers in recent years. No longer a dated tradition from the 19th century, bulk is now seen as a modern alternative to package-loaded products. Besides a more sustainable nature of transactions, bulk offers several advantages, from lower prices to the chance of portion customization and reduced food waste. However, literature identifies many setbacks for businesses invested in selling unpackaged food. Hygiene regulation in self-service systems is challenging and negatively perceived by many shoppers. Plus, a high rate of spillage, theft and losses undermines retailers' cash flows. This study focused on the market of bulk food groceries in Portugal. Prices of bulk foods were analysed and compared with the corresponding packaged alternatives, in order to assert price competitiveness. Prior literature on the subject was consulted to conceive a framework for research methods. Six interviews to storeowners operating in the Portuguese bulk foods market served as valuable insights for the investigation. Finally, an online survey with a sample of 309 bulk consumers and non-consumers presented main barriers and advantages of bulk, as well as the attitudes and perceptions that have an influence on purchase intentions. Grocery shoppers in Portugal showed a favourable inclination towards purchasing bulk. Additionally, bulk consumers are concerned about sustainability, portion control and consider price the main driver for store choice.
Comprar alimentos a granel está a tornar-se cada vez mais popular entre consumidores de produtos de mercearia. Outrora considerado uma tradição do século XIX, o granel é agora uma alternativa moderna aos produtos empacotados. Para além de representar uma forma sustentável de comércio, o granel oferece várias vantagens, desde preços mais baixos à oportunidade de controlar o tamanho das porções e reduzir o desperdício alimentar. Contudo, artigos científicos identificam algumas das contrariedades encaradas pelos negócios a granel. A regulação de higiene nos dispensadores de produtos é desafiante e vista com desconfiança por parte dos consumidores. Ademais, um elevado nível de perdas e roubo impactam negativamente os rendimentos dos retalhistas. Este estudo focou-se no mercado de venda a granel em Portugal. Produtos alimentares a granel foram comparados com as alternativas embaladas para estudar a competitividade dos preços. A literatura académica existente sobre o tema foi consultada para construir uma estrutura de pesquisa metodológica. Seis entrevistas a donos de lojas a granel a operar no mercado português serviram para complementar a investigação. Por fim, um survey online com uma amostra de 309 consumidores serviu para identificar as principais barreiras e vantagens do granel, bem como as atitudes e percepções que influenciam as decisões de compra. Os compradores de alimentos de mercearia em Portugal demonstraram intenções de compra favoráveis ao granel. Os consumidores de granel preocupam-se com a sustentabilidade, controlo de porções e consideram o preço a maior motivação para a escolha de loja.