Tesis por compendio / The overall objective of the doctoral thesis was the development of starch-based (S) biodegradable active films for food packaging applications, by applying both casting method and thermoprocessing. Different blends of S with protein material have been studied in order to improve the functional properties of the films or confer antimicrobial/antioxidant activity. The following protein materials were used: powder buttermilk (BM); lactoferrin (LF) and/or lysozyme (LZ), and bovine gelatin (BG). Ethyl lauroyl arginate (LAE, E243) was also incorporated as antimicrobial compound. Likewise, S:BG blend films, either with or without LAE, with previously oxidized S, have been studied to enhance the crosslinking of polymer chains and to improve the film properties. The films have been characterized as to their functional properties as packaging material, their antioxidant and/or antimicrobial properties, as well as their capacity for preserving different food systems, in terms of lipid oxidation and microbial spoilage. Blends of S with BM gave rise to films with a heterogeneous structure, in which the formation of a protein gel was observed when BM dispersion was heated with S at 90 ºC for 30 min. The heat treatment promoted an increase in the resistance to break and stretchability of films, together with a decrease in water vapour permeability. Only those films subjected to heat treatment exhibited antioxidant activity, probably due to the release of active peptides as a result of high temperatures. However, no antilisterial activity was observed for any film containing BM. The incorporation of LF and/or LZ into S films, obtained by the casting method, led to a partial compatibility between polymers, thus affecting the microstructure of S films, as well as leading to an rise in the glass transition temperature. Films with proteins were less extensible, especially when LF was incorporated. All of the films tested were effective at controlling the progress of lipid oxidation in pork lard, whereas only films with LF/LZ blend reduced the growth of coliforms in minced pork meat, as a result of their synergistic action. Films based on S and BG blends (1:1) were obtained by both casting method and thermo-processing. Phase separation of both polymers (stratified structure or separated domains of both polymers, respectively) was observed in both cases. The incorporation of LZ, but mainly LAE, into films, enhanced the compatibility between polymers. Thermo-processed films were more permeable to water vapour and oxygen, less rigid and resistant and more stretchable, in comparison with those films obtained by casting. While LAE incorporation improved the water vapour barrier capacity, it worsened the oxygen barrier properties, contrary to the effect produced by LZ. All films with LAE exhibited high antilisterial activity. Films based on oxidized S and BG (1:1), obtained by casting, showed a high polymer compatibility, and crosslinking between the polymer chains occurred due to the carbonyl-amino condensation reaction. As a result, the water uptake ability of the films decreased and the mechanical and barrier properties improved, although film browning was induced due to the formation of Maillard compounds. LAE incorporation implied its involvement in condensation reactions, due to its bi-functional character (carbonyl-amino), thus affecting crosslinking and the film properties. These reactive processes progressed throughout storage time, leading to an increase in the mechanical resistance and browning of the films. The obtained Maillard compounds conferred antimicrobial capacity on the films, which increased as the storage time progressed. The application of blend films of native or oxidized S and BG with LAE, for the purposes of preserving vacuum packaged chicken breast fillets, extended the shelf-life through the inhibition of bacterial growth (total viable counts; psicrotrophic, anaerobic,lactic acid bacteria and coliforms). Samples packaged i / El objetivo general de la presente tesis doctoral se basa en el desarrollo de films activos biodegradables a base de almidón (S) para su aplicación en sistemas de envasado de alimentos, por medio de dos métodos diferentes de obtención, método en húmedo por extensión y secado (casting) y método en seco (termoprocesado). Se estudiaron mezclas de S con diferentes materiales proteicos, con fin de disminuir la alta higroscopicidad de los films de S y su retrogradación a lo largo del tiempo de almacenamiento y mejorar sus propiedades funcionales, así como conferirles actividad antimicrobiana/antioxidante. Los materiales proteicos utilizados fueron los siguientes: suero de mantequilla en polvo (BM); lactoferrina (LF) y/o lisozima (LZ), y gelatina bovina (BG). El etil lauroil arginato (LAE, E243) fue también incorporado como compuesto antimicrobiano. Asimismo, se estudiaron los films mezcla de S con BG, con y sin LAE incorporado, habiendo oxidado previamente el S, para así potenciar el entrecruzado de las cadenas poliméricas y mejorar las propiedades de los films. Estos fueron caracterizados en sus propiedades funcionales como material de envase, sus propiedades antioxidantes y/o antimicrobianas, así como por su capacidad de conservación de diferentes sistemas alimentarios, en términos de su oxidación lipídica y deterioro microbiológico. Las mezclas de S con BM dieron lugar a películas con una estructura heterogénea, en las que se observó la formación de un gel proteico como resultado del calentamiento de la dispersión BM con S a 90 ºC durante 30 min. El tratamiento térmico promovió un aumento de la resistencia a la rotura y extensibilidad de los films, junto con una disminución en la permeabilidad al vapor de agua. Sólo las películas sometidas a tratamiento térmico y homogeneización con cizalla mostraron actividad antioxidante, probablemente debido a la liberación de péptidos activos en consecuencia de la alta temperatura y fuerza de cizalla aplicada Sin embargo, no se observó actividad antilisteria para ninguno de los films con BM. La incorporación de LF y/o LZ en films de S condujo a una compatibilidad parcial entre polímeros, afectando así a la microestructura de los films de S, y produciendo un aumento de la temperatura de transición vítrea y disminución de la capacidad de alargamiento de los films, especialmente cuando se incorporó LF. Todos los films resultaron eficaces en el control del progreso de la oxidación lipídica de la manteca de cerdo, mientras que sólo las películas con mezcla LF/LZ redujeron el crecimiento de coliformes en carne picada de cerdo, como resultado de su acción sinérgica. Los films basados en la mezcla S y BG (1: 1) fueron obtenidos por casting y termo-moldeado y compresión, llevando a la separación de fases entre ambos polímeros (estructura esratificada o separación de dominios de ambos polímeros, respectivamente). La incorporación de LZ, y principalmente de LAE, en los films, aumentó la compatibilidad entre ambos polímeros. Los films termoprensados fueron más permeables al vapor de agua y al oxígeno, menos rígidos y resistentes y más extensibles, en comparación con aquellos obtenidos por casting. La incorporación de LAE mejoró la capacidad de barrera contra el vapor de agua, mientras que incurrió en un empeoramiento de la barrera frente al oxígeno, contrariamente al efecto producido por la LZ. Los films con LAE, moldeados o termoprensados, mostraron una alta eficacia antilisteria. Los films basados en S oxidado y BG (1: 1), fueron obtenidos por casting y mostraron una alta compatibilidad polimérica, lo cual condujo al entrecruzado de las cadenas como resultado de la reacción de condensación carbonilo-amino producida entre ambos polímeros. En consecuencia, la capacidad de absorción de agua de los films disminuyó y se mejoraron las propiedades mecánicas y de barrera, aunque también se indujo a un pardeamiento de los films, indicando / L'objectiu general de la tesi doctoral és el desenvolupament de films actius biodegradables a base de midó (S) per a la seua aplicació en sistemes d'envasat d'aliments, amb l'utitització del mètode d'extensió i assecat (casting) i termoprocessat (barrejat en fos i termo-compressió). Es van estudiar barreges de S amb diferents materials proteics, per millorar les propietats funcionals dels films o conferir activitat antimicrobiana. Els materials protèics utilitzats van ser: sèrum de mantega en pols (BM); lactoferrina (LF) i/o lisozima (LZ), i gelatina bovina (BG). L'ètil lauroil arginat (LAE, E243) va ser també incorporat com a compost antimicrobià. Així mateix, es van estudiar els films barreja de S amb BG, amb i sense LAE, havent oxidat prèviament el S, per potenciar l'entrecreuat de les cadenes polimèriques i millorar les propietats dels films. Aquests van ser caracteritzats en les seues propietats funcionals com a material d'envàs, les seues propietats antioxidants i/o antimicrobianes, així com en la seua capacitat de conservació en diferents sistemes alimentaris, en termes de la seua oxidació lipídica i deteriorament microbià. Les barreges de S amb BM van donar lloc a films amb una estructura heterogènia, en què es va observar la formació d'un gel protèic com a resultat del calfament de la dispersió BM amb S a 90 ºC durant 30 min. El tractament tèrmic va promoure un augment de la resistència al trencament i extensibilitat dels films, juntament amb una disminució en la permeabilitat al vapor d'aigua. Només el films sotmesos a tractament tèrmic van mostrar activitat antioxidant, probablement a causa de l'alliberament de pèptids actius com a conseqüència de l'alta temperatura. No obstant això, no es va observar activitat antilisteria per cap dels films amb BM. La incorporació de LF i/o LZ en films de S obtinguts per casting va donar lloc a una compatibilitat parcial entre polímers, afectant a la microestructura dels films de S, i produint un augment de la temperatura de transició vítria. Els films amb les proteïnes van ser menys extensibles, especialment quan es va incorporar LF. Tots els films van resultar eficaços en el control de l'oxidació lipídica de la mantega de porc, mentre que només el films amb barreja LF/LZ van reduir el creixement de coliforms en carn picada de porc, com a resultat de la seua acció sinèrgica. Els films amb barreges S i BG (1: 1) van ser obtinguts per casting i termo-processat. En tots dos casos es va observar separació de fases entre els dos polímers (estructura estratificada o separació de dominis d'ambdós polímers, respectivament). La incorporació de LZ, i principalment de LAE, en els films, va augmentar la compatibilitat entre tots dos polímers. Els films termo-processats van ser més permeables al vapor d'aigua i l'oxigen, menys rígids i resistents i més extensibles, en comparació amb els obtinguts per càsting. La incorporació de LAE va millorar la capacitat de barrera al vapor d'aigua, a l'hora que va disminuir la capacitat de barrera davant l'oxigen, contràriament a l'efecte produït per la LZ. Tots els films amb LAE, van mostrar una alta capacitat antilisteria. Els films amb S oxidat i BG (1: 1), van ser obtinguts per casting i van mostrar una alta compatibilitat dels polímers, tot produint entrecreuat de les cadenes com a resultat de la reacció de condensació carbonil-amino. En conseqüència, va disminuir la capacitat d'absorció d'aigua dels films i es van millorar les propietats mecàniques i de barrera, encara que es va promoure l'enfosquiment dels films, cosa que indica la formació de compostos de Maillard. La incorporació de LAE va implicar la seua participació en les reaccions de condensació, a causa del seu caràcter bi-funcional (carbonil-amino), el que va afectar a l'entrecreuat i les propietats dels films. Aquests processos reactius van progressar al llarg del temps d'emmagatzematge, donant lloc a un augment de l / Moreno Marro, O. (2017). Starch-protein active films for food preservation [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/80616 / Compendio

Submitted by Raquel Vergara Gondran (raquelvergara38@yahoo.com.br) on 2016-04-27T00:00:15Z No. of bitstreams: 1 fabiano de andrade ferreira -filmes nanocompsitos antimicrobianos obtidos - fabiano.pdf: 1339665 bytes, checksum: 6d9b23ae68b29ab5bf3a34d2d80e6ce3 (MD5) / Approved for entry into archive by Gilmar Barros (gilmargomesdebarros@gmail.com) on 2016-04-29T21:16:14Z (GMT) No. of bitstreams: 1 fabiano de andrade ferreira -filmes nanocompsitos antimicrobianos obtidos - fabiano.pdf: 1339665 bytes, checksum: 6d9b23ae68b29ab5bf3a34d2d80e6ce3 (MD5) / Made available in DSpace on 2016-04-29T21:16:14Z (GMT). No. of bitstreams: 1 fabiano de andrade ferreira -filmes nanocompsitos antimicrobianos obtidos - fabiano.pdf: 1339665 bytes, checksum: 6d9b23ae68b29ab5bf3a34d2d80e6ce3 (MD5) Previous issue date: 2014 / As indústrias de alimentos, entre elas a indústria pesqueira, geram uma grande quantidade de resíduos que, quando descartados de maneira inadequada, podem causar sérios problemas para o meio ambiente. O objetivo deste trabalho foi desenvolver e avaliar filmes antimicrobianos nanocompósitos, de proteínas recuperadas da carne mecanicamente separada de pescado de baixo valor comercial, incorporados com óleos essenciais. Para este fim, utilizou-se proteína recuperada da corvina (Micropogonias furnieri), glicerol, montmorilonita e óleos essenciais de orégano e cravo. A proteína recuperada foi caracterizada quanto a sua composição proximal e funcionalidade apresentando um conteúdo proteico de 94,62% em base seca. Na obtenção dos filmes utilizou-se a técnica de casting onde forma realizados vários experimentos variando a composição da solução filmogênica em relação à quantidade de proteína, glicerol, nanoargila montmorilonita e óleos essenciais de orégano e de cravo. Os filmes foram caracterizados em relação à opacidade, solubilidade em água, propriedades mecânicas e permeabilidade ao vapor de água, sendo selecionados os filmes incorporados com óleos essenciais que apresentaram os melhores resultados, enfatizando-se a característica de elongação. A atividade antimicrobiana dos filmes, em relação à Escherichia coli, Staphylococcus coagulase positiva e Salmonella Enteretidis, foi verificada pelo método de difusão em disco. Os filmes incorporados com óleos essenciais na concentração mínima de 1 mL foram os que desenvolveram atividade antimicrobiana em relação aos microrganismos avaliados. As soluções filmogênicas destes filmes foram utilizadas como revestimento através da técnica dipping para avaliar as mudanças ocorridas em camarões branco (Litopenaeus vannamei) crus, descascados e refrigerados a 4±1°C durante 10 dias. Foram avaliadas características como perda de massa, cor, firmeza, pH, N-BVT, TBARS e crescimento microbiológico sendo que, em todos os tratamentos, onde os camarões foram revestidos com as soluções que continham óleo essencial os resultados foram melhores do que o tratamento controle onde a solução não era incorporada de óleo essencial. Neste aspecto o tratamento que continha em sua formulação 4,0 g de proteína recuperada, 1,35 g de glicerol, 0,6 g de montmorilonita, 1,0 mL de óleo essencial de orégano e 1,0 mL de óleo essencial de cravo foi o que apresentou o melhor resultado em todas as características analisadas. O filme correspondente a este tratamento também foi avaliado em relação a sua microestrutura e propriedades térmicas, onde foi verificado que a incorporação dos óleos essenciais altera a superfície do filme deixando-a mais porosa em relação ao filme sem óleos essenciais, por outro lado, a presença de óleos essenciais na estrutura do filme aumentou a estabilidade térmica do mesmo comparando com o filme sem óleos. Os resultados indicam que os filmes incorporados com óleos essenciais de orégano em uma concentração de 1% (v/v) apresentaram ação inibitória em relação aos microrganismos avaliados e que a vida útil dos camarões revestidos com soluções filmogênicas contendo óleos essenciais, em relação aos camarões sem revestimentos, aumentou de 5 para 8 dias. / The food industries, including the fishing industry, generate a lot of waste when disposed of improperly, can cause serious problems for the environment. The aim of this study was to develop and evaluate antimicrobial nanocomposite films from recovered proteins of mechanically separated fish meat of low commercial value, incorporated with essential oils meat. To this end, we used protein recovered croaker (Micropogonias furnieri), glycerol, montmorillonite and essential oils of oregano and clove. The recovered protein was characterized with respect to their composition and function having a protein content of 94.62% on a dry basis. To obtain the films we used the technique of casting where they performed several experiments varying the composition of the film solution for the quantity of protein, glycerol, montmorillonite nanoclay and essential oils of oregano and clove. The films were characterized with respect to opacity, water solubility, mechanical properties and permeability to water vapor, being selected films incorporated with essential oils that showed the best results, emphasizing the characteristic elongation. The antimicrobial activity of the films in relation to Escherichia coli, Staphylococcus coagulase positive and Salmonella Enteretidis was verified by the disk diffusion method. Films incorporated with essential oils at the minimum concentration of 1mL were those who developed antimicrobial activity towards microorganisms evaluated. The film formation solutions of these films were used as coating by dipping technique to evaluate changes in white shrimp (Litopenaeus vannamei) raw, peeled and chilled at 4 ± 1°C for 10 days. Characteristics such as weight loss, color, firmness, pH, TVB-N, TBARS and microbiological growth were being evaluated, in all treatments, where shrimp were coated with solutions containing essential oil were better than treatment control where the solution was not incorporated essential oil. In this respect the treatment that contained in its formulation 4.0 g of recovered protein, 1.35 g glycerol, 0.6 g montmorillonite, 1.0 mL of oregano essential oil and 1.0 mL of clove essential oil showed the best results in all traits. The film corresponding to this treatment was also evaluated for its thermal properties and microstructure, which found that the incorporation of essential oils alters the film surface making it more porous compared to the film without essential oils, on the other hand, presence of essential oils in the structure of the film increased thermal stability compared with the same film without oils. The results indicate that the films incorporated with oregano essential oils in a concentration of 1% (v / v) showed inhibitory activity towards microorganisms evaluated and that the life of shrimp coated film formation solutions containing essential oils in relation to shrimp without coatings increased from 5 to 8 days.

This thesis has an approved one-year embargo applied to it. Please, refer to the corresponding forms, and please, so not publish immediately until the embargo has been sorted out. The thesis contains two unpublish papers and patents pending. Thank you! / Conventional single-use plastic packaging has contributed significantly to the health and well-being of our society but also negatively impacted our environment due to its persistence after use. Since recycling is not a complete solution, rapidly biodegradable materials like thermoplastic starch (TPS) blends offer a more sustainable alternative. Additionally, to stave off the premature breakdown of starch-containing materials as well as extend the shelf life of enclosed foods, microbial control strategies need to be developed. To overcome the inherent brittleness of TPS, this work explores the potential of xylitol and erythritol as melt plasticizers for waxy corn starch (̴100% amylose). Characterizations revealed that both xylitol and erythritol can gelatinize and plasticize starch under 25% wt. Particularly, xylitol demonstrated superior plasticizing and compatibilizing effects, leading to a ductile TPS packaging film with uncharacteristically high elongation at break (EB, 422% ± 48%). The ductile TPS was blended with up to 70% Ecovio bioplastic without requiring compatibilizers and retaining much of its EB value (298 ± 24%). Using xylitol as a melt plasticizer also enhanced the mechanical and hydrophobic qualities of the TPS/Ecovio film as well as its oxygen permeability and puncture extension. Furthermore, polymerized curcumin copolymer (PCEG) was investigated as a grafted coating onto the developed TPS/Ecovio® blend. The antimicrobial activity of PCEG and PCEG coating film was evaluated against foodborne bacteria. The polymerized curcumin by itself demonstrated antimicrobial activity against the gram-negative bacteria Escherichia coli BL21 and Pseudomonas aeruginosa PA01, as well as the gram-positive bacterium Staphylococcus aureus. Additionally, the PCEG-coated films showed surface inhibition of Glutamicibacter soli (IAI-3), a gram-positive bacterium making polymerized curcumin copolymer coatings a suitable approach to add antimicrobial features in thermoplastic starch composites for biodegradable food packaging. / Thesis / Master of Applied Science (MASc) / Canada's Zero Plastics initiative represents a commitment to the environment while upholding the advancements in food safety and public health that come with single-use food packaging. Achieving this balance demands the creation of novel materials. These materials should mimic the qualities of synthetic polymers but have the added ability to decompose naturally in the environment upon reaching the end of their utility. A significant challenge in this effort is preventing the premature degradation of starch-containing packaging materials. Moreover, extending the shelf life of the food they enclose is equally crucial. To solve this paradox, the development of microbial control strategies becomes imperative. This study highlights the antimicrobial potential of a polymerized curcumin copolymer (PCEG) as a coating on a blend of thermoplastic starch (TPS)/xylitol/Ecovio®, creating an innovative packaging film. The curcumin copolymer coating exhibited antimicrobial properties, suggesting its potential use in thermoplastic starch composites for biodegradable food packaging.

La mondialisation des marchés, les changements d’habitudes de consommation et les préoccupations croissantes concernant la sécurité alimentaire et l’environnement sont des éléments moteurs pour le développement des films d’emballage comestibles/biodégradables antimicrobiens. Une utilisation en masse de ce type de film est dépendante principalement des verrous technologiques car le mode de fabrication actuellement utilisé pour ce genre de film consiste à utiliser un procédé (voie solvant) qui n’est pas toujours adapté à une production importante et continue. L’étude présentée ici permet de montrer la possibilité d’obtenir des films comestibles antimicrobiens à partir de caséinate de sodium en utilisant les procédés traditionnels de la plasturgie : extrusion bi-vis et extrusion-gonflage. Grâce aux optimisations des paramètres d’élaboration tels que la température de transformation, le taux de cisaillement et le taux de plastifiant, les matériaux contenant un agent actif naturel : le lysozyme, la nisine ou la natamycine ont gardé en partie leurs activités antimicrobiennes. Par des caractérisations mécaniques et physico-chimiques des films thermoplastiques, il a été démontré que ces films ont des propriétés mécaniques et barrières similaires à ceux fabriqués par voie solvant. Ces propriétés dépendent principalement du taux de plastifiant. Ainsi, il est possible de fabriquer des films comestibles antimicrobiens de caséinate de sodium avec de bonnes propriétés mécaniques et barrières qui ne sont pas affectées par la transformation thermomécanique et qui peuvent être adaptées en fonctions des applications en variant le taux de plastifiant / Because food market becomes international, consumers are changing their habits and they are more concerned about food security and environmental issues, there are driving forces for the development of edible/biodegradable antimicrobial packaging films. However, fabrication process (solution-casting) of these kinds of films isn’t always suitable for a continuous industrial big production. The present study demonstrates the suitability of sodium caseinate based edible antimicrobial films to be fabricated by some conventional plastic transformation processes: twinscrew extrusion and blown-film extrusion. Thanks to the optimizations of elaboration parameters such as extrusion temperature, shear and plasticizer ratio, the materials incorporated with one of the following active agents: lysozyme, nisin or natamycin, partially kept their antimicrobial activity. Physical-chemical film characterization of films emphasized that the type of transformation process doesn’t have any influence on tensile or gas barrier properties. These properties are mainly affected by plasticizer type and content. Thus, sodium caseinate based edible antimicrobial films can be produced successfully by thermo-mechanical processes without losing good mechanical and gas barrier properties