This body of work investigates various techniques for the surface modification of food contact materials for use in food packaging and processing applications. Nanoscale changes to the surface of polymeric food packaging materials enables changes in adhesion, wettability, printability, chemical functionality, and bioactivity, while maintaining desirable bulk properties. Polymer surface modification is used in applications such as antimicrobial or non-fouling materials, biosensors, and active packaging. Non-migratory active packagings, in which bioactive components are tethered to the package, offer the potential to reduce the need for additives in food products while maintaining safety and quality. A challenge in developing non-migratory active packaging materials is the loss of biomolecular activity that can occur when biomolecules are immobilized. Polyethylene glycol (PEG), a biocompatible polymer, is grafted from the surface of ozone treated low-density polyethylene (LDPE) resulting in a surface functionalized polyethylene to which a range of amine-terminated bioactive molecules can be immobilized. The grafting of PEG onto the surface of polymer packaging films is accomplished by free radical graft polymerization, and to covalently link an amine-terminated molecule to the PEG tether, demonstrating that amine-terminated bioactive compounds (such as peptides, enzymes, and some antimicrobials) can be immobilized onto PEG-grafted LDPE in the development of non-migratory active packaging. Fouling on food contact surfaces during food processing has a significant impact on operating efficiency and can promote biofilm development. Processing raw milk on plate heat exchangers results in significant fouling of proteins as well as minerals, and is exacerbated by the wall heating effect. An electroless nickel coating is co-deposited with polytetrafluoroethylene onto stainless steel to test its ability to resist fouling on a pilot plant scale plate heat exchanger. Further work was performed to test the stability of non-fouling material after extended exposure to an alkali detergent or acid sanitizer formulated for clean-in-place procedures in dairy processing facilities. Additionally, the anti-corrosive property of the surface coating was tested on carbon steel against chlorine ions, a common corrosive agent found in the food industry. Accelerated corrosion and long-term chemical exposure studies were conducted to measure the coating stability against the harsh corrosive agents.

The quality of many beverages and food products is compromised by the presence of low molecular weight aldehydes. Aldehydes are commonly formed during storage by the oxidation of lipids or are introduced as migrants from polymeric packaging material. The objective of this project was to evaluate the effectiveness of three aldehyde scavenging agents, blended into poly(ethylene terephthalate) (PET) films, in removing an aliphatic series of aldehydes from an acidified aqueous model solution (pH 3.6) during storage. Aldehyde concentration in solution was determined by an improved high performance liquid chromatography method involving the formation of aldehyde-hydrazine complexes by 2,4-dinitrophenylhydrazine. Storage of 25 μM mixtures of acetaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and caproaldehyde in contact with PET films blended with 5% poly(m-xylylene adipamide) (nylon MXD6), D-sorbitol, or alpha-cyclodextrin reduced the concentration of each aldehyde in solution by 21 to 90% after 14 days of exposure. D-sorbitol and alpha-cyclodextrin aldehyde scavenging PET films were the most effective treatments for the reduction of aldehydes from solution showing similar average reductions for the five aldehyde species of 11.4 and 13.8 μM, respectively. PET films blended with nylon MXD6 were less effective in removing aldehydes from solution showing an average reduction of 8.4 μM for the five aldehyde species. However, nylon MXD6 proved to the most efficient aldehyde scavenging agent tested. D-sorbitol and alpha-cyclodextrin blends include 45 and 17 times more aldehyde scavenging sites then nylon MXD6 blends, but only showed 26 and 39% improvements in aldehyde scavenging ability when compared to nylon MXD6 blends. Aldehyde scavenging films demonstrated selective scalping preferring smaller molecular weight aldehydes, such as acetaldehyde, propionaldehyde, and butyraldehyde, more than larger aldehydes, valeraldehyde and caproaldehyde. Partition coefficients for smaller aldehydes were 3 to 6 times greater for aldehyde scavenging films then control film. / Ph. D.

Tesis por compendio / Packaging plays an important role in ensuring food safety and quality. The development antimicrobial packaging enables actively inhibiting/killing the spoilage microorganisms, and thus extending food product's shelf life. Generally, 50% shelf life extension is possible. The interest for using metallic nanoparticles in active packaging derives from its superior antimicrobial efficacy and no negative impact on the food sensory properties. In this thesis, the packaging material of concern is a PLA (Polylactic Acid) coated paper incorporating zinc oxide nanoparticles (ZnO NPs) in the coating layer. The material was characterized and its antimicrobial activity was evaluated. The SEM images show that the nanoparticles were homogenously distributed across the surface thanks to its surface modification. Antimicrobial assay indicates that the active material was effective in inactivating E. coli and S. aureus. Furthermore, E. coli was found to be more susceptible to this type of agent, showing 3.14 log reduction for 0.5 wt% agent loading in the PLA coating layer. This result was compared across the publications using the same agent for treating both Gram-positive and Gram-negative microorganisms. The discrepancy between the results can be explained by the fact that ZnO nanoparticles have multiple action mechanisms, and different antimicrobial testing methods may activate part of the action mechanisms. On the other hand, recyclability is regarded as an important attribute for paper-based packaging material, as it enables to conserve the resources and reduce the environmental impacts. Accordingly, when it comes to the nano-enabled paper packaging material, recyclability should be maintained. In this case, a recyclability test was carried out in a lab-scale paper recycling line. The protocol was based on a method adapted from the ATICELCA MC501-13, which enabled to recover over 99% of the solids material. The mass balance result indicates that 86%-91% zinc oxide nanoparticles ended up in the rejected material stream, mostly embedded within the polymer coating; whereas 7%-16% nanoparticles ended up in the accepted material stream. Besides, the tensile strength of the recycled handsheets suggests that the nano-enabled coating had no negative impacts on the recovered fibre quality. Active packaging plays a positive role in reducing food losses. If food and packaging are considered as a whole system, its overall environmental impact can be justified by incorporating the food loss reduction due to the application of active packaging. The LCA calculation shows that a breakeven point can be easily achieved for the case of red meat products of high environmental impact. / El envase juega un papel importante asegurando la seguridad y calidad de los alimentos. El desarrollo de envases activos, especialmente envase antimicrobiano, permite inhibir o matar los microorganismos causantes del deterioro de los alimentos, alargando por tanto su vida útil. De forma general es posible extender la vida útil de los alimentos en un 50%. El interés por el uso de nanopartículas metálicas en el envasado activo se deriva de su gran efectividad antimicrobiana sin causar un efecto negativo en sus propiedades sensoriales. En la presente tesis, se ha desarrollado un papel recubierto de PLA (ácido poliláctico) con nanopartículas de óxido de zinc (ZnO NPs) incorporadas en la capa de recubrimiento. Se ha caracterizado el material y se ha evaluado su capacidad antimicrobiana. Las imágenes obtenidas mediante SEM muestran que las nanopartículas fueron distribuidas a lo largo de la superficie gracias a su modificación. Los ensayos de efectividad antimicrobiana indicaron una actividad del material frente a E. coli y a S. aureus. Además, E. coli resultó ser más susceptible a este agente activo incorporado al 0.5 % en peso en el recubrimiento de PLA, mostrando una reducción de 3.14 log. Este resultado fue comparado con publicaciones donde se emplearon los mismos agentes activos para frente a microorganismos Gram-positivos y Gram-negativos. Las discrepancias encontradas entre los resultados pueden deberse a que las nanopartículas de ZnO tienen múltiples mecanismos de acción, y los diferentes métodos de ensayo poder estimular parte de estos mecanismos. Por otra parte, el reciclado juega un importante papel en la conservación de los recursos y en la reducción de los impactos medioambientales. Por tanto, cuando se trata de un material de envase de papel con sustancias de tamaño nano, el reciclado debe tratarse adecuadamente. El ensayo de reciclabilidad fue llevado a cabo a escala laboratorio en una línea de reciclado de papel. El protocolo de ensayo se basó en el método adaptado de ATICELCA MC501-13, permitiendo una recuperación del 99% de material sólidos. Los resultados del balance de materia indicaron que el 86%-91% de las nanopartículas de óxido de zinc llegaron al flujo de material de rechazo, principalmente mezclado en el recubrimiento polimérico. Además, los resultados de tracción de las láminas recicladas sugieren que el recubrimiento con partículas nano no tiene un efecto negativo sobre la calidad de la fibra recuperada. El envase activo juega un papel positivo en la reducción de los residuos alimentarios. Como resultado del uso del envase activo, considerando el envase y el alimento como un todo, el impacto ambiental sobre este sistema completo puede ser compensado por la reducción de pérdidas de alimentos. El cálculo LCA muestra que el punto de equilibrio se puede conseguir fácilmente en el caso de productos de carne roja de elevado impacto ambiental. / L'envàs té un paper prou important en la seguretat i la qualitat del aliments. El desenvolupament dels envasos actius, especialment l'envàs antimicrobià, el qual permeteix l'inhibició o mort dels microorganismes que produeixen el deteriorament dels aliments i, per tant, allargant la seua vida útil. De manera general, es possible l'allargament de la vida útil dels aliments en un 50%. L'interès per la utilització de nanopartícules metàl·liques en l'envasat actiu es deriva de la seua gran efectivitat antimicrobiana sense produir un efecte negatiu en les seus propietats sensorials. En aquesta present tesis, s'ha desenvolupat un paper recobert de PLA (àcid polilàctic) amb nanopartícules d'òxid de zinc (ZnO NPs) incorporades a la capa de recobriment. S'ha caracteritzat el material i s'ha avaluat la seua capacitat antimicrobiana. Les imatges obtingudes per mitjà del SEM mostren que les nanopartícules foren distribuïdes en tota la superfície gràcies a la seua modificació. Els assajos d'efectivitat antimicrobiana varen indicar una activitat del material front a E.coli i a S. aureus. A més, E. coli va resultar ser més susceptible a aquest agent actiu incorporat al 0.5 % en pes en el recobriment de PLA, mostrant una reducció de 3.14 log. Aquest resultat va ser comparat amb publicacions on es van emprar els mateixos agents actius front a microorganismes Gram-positiu i Gram-negatiu. Les discrepàncies trobades entre els resultats poden deure's a que les nanopartícules de ZnO tenen diversos mecanismes d'acció, i els diferents mètodes d'assaig poder estimular part d'aquestes mecanismes. Per altra banda, el reciclatge també té un paper important en la conservació dels recursos i en la reducció dels impactes mediambientals. Per tant, quan es tracta d'un material d'envàs de paper amb substàncies de la grandària 'nano', el reciclatge ha de tractar-se adequadament. El assaig de reciclabilitat va ser dut a terme a escala de laboratori en una línia de reciclatge de paper. El protocol de l'assaig es va basar en el mètode adaptat d'ATICELCA MC501-13, permetent una recuperació del 99% del material sòlid. Els resultats del balanç de matèria van indicar que el 86-91% de les nanopartícules d'òxid de zinc varen arribar al fluix material de rebuig, principalment mesclat en el recobriment polimèric. A més, els resultats de tracció de les làmines reciclades suggereixen que el recobriment amb nanopartícules nano no tenen un efecte negatiu sobre la qualitat de la fibra recuperada. L'envàs actiu juga un paper positiu en la reducció dels residus alimentaris. Com a resultat de l'ús de l'envàs actiu, considerant l'envàs i l'aliment com un tot conjunt, l'impacte ambiental sobre aquest sistema complet pot ser compensat per la reducció de pèrdues d'aliments. El càlcul LCA mostra que el punt d'equilibri es pot aconseguir fàcilment en el cas de productes de carn roja d'elevat impacte ambiental. / Zhang, H. (2016). Sustainability assessment of active packaging incorporating nanomaterials [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/75348 / Compendio

<p>Predmet doktorske disertacije je razvoj aktivnog jestivog omotača na bazi hitozana sa dodatkom etarskih ulja začinskog bilja i pčelinjeg voska, kao i njegova aplikacija u cilju produženja održivosti suve fermentisane Petrovačke kobasice.<br />U cilju realizacije programa teze, formirane su tri osnovne grupe filmova: hitozan-etarsko ulje origana, hitozan-etarsko ulje kima i hitozan-etarsko ulje kima-pčelinji vosak. Paralelno sa pripremom filmova, proizvedeni su i odgovarajući kolagen-hitozan laminirani omotači. U pripremi filmova i omotača su primenjena dva vlažna postupka. Filmovi su dobijeni razlivanjem, a laminirani omotači premazivanjem filmogene emulzije preko kolagenog omotača. Tokom razvijanja, ispitivan je uticaj različitih parametara na svojstva dobijenih filmova: viskozitet i koncentracija hitozana, dodatak polietilenoksida kao kopolimera u film, dodatak različite koncentracije etarskog ulja, uslovi me&scaron;anja i temperature, kao i dodatak različite koncentracije pčelinjeg voska.<br />Dobijeni filmovi i omotači su okarakterisani ispitivanjem osobina značajnih za primenu materijala, a to su fizičko-mehanička (debljina, zatezna jačina i izduženje pri kidanju), strukturna (ATR-FTIR spektrometrija i elektron skenirajuća mikroskopija), fizičko-hemijska (sadržaj vlage, bubrenje, rastvaranje), barijerna (propustljivost gasova i brzina propustljivosti vodene pare) svojstva i biolo&scaron;ka aktivnost (antioksidatino i antimikrobno delovanje). Na osnovu detaljne karakterizacije, odabrani su filmovi i omotači optimalnih svojstava za primenu u za&scaron;titi Petrovačke kobasice tokom skladi&scaron;tenja.<br />Ispitano je dejstvo premaza na očuvanje kobasice sa i bez dodate komercijalne i autohtone starter kulture. Efekat primene premaza izučavan je ispitivanjima parametara kvaliteta Petrovačke kobasice i to, praćenjem promene sadržaja vlage, pH vrednosti, boje, oksidacije lipida, kao i senzorne ocene mirisa i ukusa ove kobasice tokom skladi&scaron;tenja.<br />Na osnovu prikazanih rezultata, može se zaključiti da je sintetisan aktivan jestivi premaz na bazi hitozana optimizovanih barijernih, fizičko-hemijskih, antioksidativnih i antimikrobnih svojstava. Sintetisani premaz ima manju brzinu propustljivosti vodene pare, uz očuvanu nisku propustljivost za gasove, smanjenu osetljivost na delovanje vlage i izraženiju antimikrobnu i antioksidativnu aktivnost. Upkos optimizovanim barijernim svojstvima za vodenu paru, hitozanski premaz sa dodatkom etarskih ulja i/ili pčelinjeg voska nije imao efekta u očuvanju sadržaja vlage suve fermentisane kobasice tokom skladi&scaron;tenja. Ispitivani premazi su doprineli očuvanju boje preseka kobasice, ali ovaj efekat nije bio potpuno izražen kod svih tipova kobasice i svih premaza. Sva tri parametra za praćenje oksidativnih promena u kobasici ukazuju na to da je nano&scaron;enjem hitozanskog premaza sa etarskim uljem origana ili kima i pčelinjim voskom, kobasica efikasno za&scaron;tićena od nepoželjnih oksidativnih promena. Između eksperimenata se može povući paralela, da hitozanski premaz pokazuje za&scaron;titni efekat prema senzornom profilu mirisa i ukusa, do blizu 5 meseci skladi&scaron;tenja. Na ovom nivou razvoja premaza, on se može preporučiti kao pomoćan ambalažni materijal.</p> / <p>The subject of the doctoral dissertation is development of active edible coating based on chitosan with added herb essential oils and beeswax, as well as its application for dry fermented sausage shelf life extension.<br />In order to realize the program of investigation, three basic groups of films were produced: chitosan-essential oil of oregano, chitosan-essential oil of caraway and chitosan-essential oil of caraway-beeswax. Simultaneously with the production of films, collagen-chitosan laminated casings were produced. In the production of films and laminated casings, two wet methods were applied. Films were produced by casting method, while laminated casings were produced by coating collagen casing with filmogenic emulsion. During production, the influence of different parameters on properties of produced films and casings was investigated: viscosity and concentration of chitosan, addition of poly (ethylene oxide) as copolymer in the films, addition of different concentration of essential oils, mixing and temperature conditions, as well as addition of different concentration of beeswax.<br />Produced films and laminated casings were characterized by the investigation of properties that are important for material application, namely physical-mechanical (thickness, tensile strength and elongation at break), structural (ATR-FTIR spectrometry and scanning electron microscopy), physical-chemical (water content, swelling, solubility), barrier (gas permeability and water vapor transmission rate) properties and biological activity (antioxidative and antimicrobial activity). Based on detail characterization, films and casings with optimal properties were selected for application on Petrovac sausage with and without the addition af commercial or indigenous starter culture for preservation during storage.<br />The effect of coating application was analyzed based on the quality parameters of Petrovac sausage, namely: water content, pH value, color, lipid oxidation and sensory profile of taste and odor of the sausage during storage.<br />Based on presented results, it can be concluded that active edible coating based on chitosan was synthesized, with optimized barrier, physical-chemical, antioxidant and antibacterial properties. Synthesized coating has lower water transmission rate with preserved low gas permeability, lowered sensibility to humidity and more pronounced antimicrobial and antioxidant activity. Despite optimized water vapor barrier properties, chitosan coating with addition of essential oils and/or beeswax did not show the effect in preserving the water content in the sausage during storage. Investigated coatings contributed to the preservation of core color of the sausage, but this effect was not fully expressed in all types of sausages and coatings. All three parameters for investigation of oxidative changes in the sausage showed that chitosan coating with essential oils of oregano and caraway and beeswax efficiently preserved sausage from unwanted oxidative changes. Mutual conclusion from the experiments is that chitosan coating shows preservative effect on the sensory profile of taste and odor till approximately 5 months of storage. On this level of coating development, it can be recommended as auxiliary packaging material.</p>

Les emballages actifs permettent d’étendre la durée de conservation des aliments, réduisent l'utilisation d'additifs et de conservateurs dans les préparations alimentaires, préservent mieux les saveurs et la qualité des aliments. La libération contrôlée des antioxydants à partir d'emballages alimentaires étend la stabilité des produits (oxydation des lipides réduite) par enrichissement continu en antioxydants alimentaires en surface de l’aliment. L'objectif général du présent travail était d'étudier l'applicabilité de l'acide poly lactique (PLA, polymère biodégradable fabriqué industriellement) comme l'emballage actif. Pour cela, nous avons choisi plusieurs antioxydants synthétiques ou naturels, comme l'alpha-tocophérol, le palmitate d'ascorbyle, le BHA, le BHT, le gallate de propyle et le TBHQ pour produire les emballages antioxydants. En premier lieu, le mode de d’inclusion de ces antioxydants dans la matrice de PLA et leurs effets sur diverses propriétés structurale, thermique, mécanique et barrière du PLA ont été étudiés. L'étude la libération des antioxydants a été réalisée à partir de films de PLA-antioxydants en contact avec trois simulateurs d'aliments (95%, 50%, et 10% d'éthanol) à deux températures (20°C et 40°C). Les résultats ont montré que le PLA a la capacité de contenir et de libérer des antioxydants dans certains produits alimentaires. Enfin, un modèle mathématique basé sur des relations quantitatives structure/propriété (QSPR) a été développé pour prédire la diffusion antioxydants dans les systèmes aliments simulés /emballage actif / Active packaging generates longer shelf-life foods, lower usage of additives and preservatives in food formulations, higher protection of flavors and higher food qualities. Antioxidant controlled release from packaging provides longer food stability (reduced lipid oxidation) by continuously liberating antioxidants at food surface. The overall objective of the present work was to study the suitability of Poly Lactic Acid (PLA, biodegradable polymer industrially produced) as active packaging. We chose various synthetic or natural antioxidants including alpha-tocopherol, Ascorbyl palmitate, BHA, BHT, Propyl gallate and TBHQ to produce the antioxidant packaging. Firstly, the mode of incorporation of these antioxidants in PLA matrix and also their potential effects on diverse structural, thermal, mechanical and barrier properties of PLA were investigated. The release study of antioxidants was accomplished from PLA-antioxidants films into three food simulants, i.e. 95%, 50%, and 10% ethanol at two temperatures (20°C and 40°C). The results showed that PLA has the capability for being as a suitable carrier for antioxidant-active packaging for some food products. Finally, a mathematical model based on quantitative structure property relationships (QSPR) was developed to predict antioxidant diffusion in food simulant/ active packaging system

Orientador: Márcia Regina de Moura Aouada / Resumo: A crescente preocupação em se consumir produtos que sejam ecologicamente corretos tem motivado pesquisas no desenvolvimento de novos materiais. Nesse sentido, filmes à base de polímeros naturais têm sido desenvolvidos com o objetivo de substituir parcialmente a utilização dos polímeros tradicionais. A utilização desses filmes, além de diminuir a geração de resíduos plásticos descartados no meio ambiente, podem ainda exercer a função de embalagem ativa, estendendo a vida útil dos alimentos. O presente trabalho consiste na elaboração de novos filmes comestíveis à base de gelatina e nanoemulsão de óleos essenciais de manjerona e de pimenta-preta. A gelatina é um polímero natural, biocompatível e biodegradável, possuindo boa capacidade de formar filmes flexíveis. Os óleos essenciais de manjerona e de pimenta-preta possuem boa aceitação por parte dos consumidores, além de excelentes propriedades antioxidantes e antimicrobianas. Quando adicionados às matrizes poliméricas em forma de nanoemulsão, pode contribuir para a diminuição da permeabilidade a vapores de água e aumentar a tenacidade dos filmes. Visando a melhoria da resistência mecânica dos filmes, dispersão de argilas vem sido incorporadas as dispersões filmogênicas. Nesse trabalho, foi utilizada a cloisite Na+. Os filmes produzidos foram caracterizados quanto à análise subjetiva, permeabilidade ao vapor de água, propriedade mecânicas, propriedades térmicas, difração de raios-x, ângulo de contato e microestruturais. As nanoem... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The growing concern to consume products that are ecologically correct has motivated the study in the development of new materials. In this sense, films based in natural polymers have been created with the aim of replacement of the traditional polymers. The use of these films behind to decreasing the generation of plastic waste in the environment, it can still be active packaging, extending the food shelf-life. This present study consists in the elaboration of a film based in gelatin and marjoram and black pepper essential oils nanoemulsions. Gelatin is a natural, biocompatible and biodegradable polymer, it has good flexible and film forming ability. The marjoram and black pepper essential oil has a good acceptance by the consumers, as well as excellent antioxidant and antimicrobial properties. When incorporated to polymer matrices by the nanoemulsions way, they can contributed to the reduction of water vapor permeability and increase film tenacity. By the aim of improve the mechanical proprieties, clay dispersions had been incorporated in the film dispersions. In this study Na+ cloisite was used. The produced films were characterized by the subjective analysis, water vapor permeability, mechanical properties, thermal properties, x-ray diffusion, contact angle and microstructural. The nanoemulsions characterized by the particle size, presented results between 250 and 181nm to black pepper, and 82 and 47nm to marjoram essential oil. Related to the water vapor permeability and t... (Complete abstract click electronic access below) / Mestre

Aliado ao fato dos biomateriais ainda serem pouco explorados pelas indústrias alimentícias, este trabalho propôs o desenvolvimento de embalagens que sejam, além de biodegradáveis, também ativas através do uso de um agente antimicrobiano natural capaz de inibir a proliferação de fungos correntes em produtos de panificação (Penicillium commune e Eurotium amstelodami). Primeiramente, filmes biodegradáveis a base de fécula de mandioca foram elaborados pela técnica de casting, usando açúcares e glicerol como plastificantes. O aumento do conteúdo de glicerol causou diminuição da resistência máxima à tração e elevação dos valores de propriedades de barreira. Numa segunda etapa do trabalho, a introdução de nanopartículas de argila esmectita influenciou positivamente as propriedades de barreira dos filmes, devido à diminuição observada nos valores de permeabilidade ao vapor de água e coeficiente de permeabilidade ao oxigênio. Nesta fase, a variação do conteúdo de glicerol também afetou significativamente as propriedades mecânicas e de barreira dos filmes biodegradáveis. As concentrações inibitórias mínimas dos óleos essenciais de cravo e de canela contra os fungos estudados foram definidas e o óleo essencial de canela foi selecionado, para ser incorporado aos filmes biodegradáveis, em três conteúdos distintos, pois foi o composto que mostrou uma inibição mais eficiente. A atividade antimicrobiana dos filmes biodegradáveis com incorporação de óleo essencial de canela foi testada sobre os micro-organismos escolhidos através de testes de difusão em halo, cujos resultados foram suficientes para demonstrar o potencial ativo da embalagem desenvolvida. Como método alternativo de incorporação do agente antimicrobiano, gás carbônico (CO2) em estado supercrítico foi utilizado como solvente. Os resultados obtidos foram promissores, uma vez que se observou incorporação de agente antimicrobiano dentro da matriz polimérica em quantidade suficiente para inibir a proliferação dos fungos testados. / This work concerned the development of biodegradable and active packaging based on cassava starch and natural antimicrobial agents that efficiently inhibit growth of fungi commonly found in bread products (Penicillium commune and Eurotium amstelodami). Biodegradable films were prepared by the casting technique, using sugars and glycerol as plasticizers. An increase in glycerol content caused a decrease in tensile strength and an elevation on barrier properties results. In a second phase of the work, incorporation of nanoclays diminished water vapor and oxygen permeability thus improving film packaging properties. Two antimicrobial agents were tested (cinnamon and clove essential oils) and cinnamon essential oil was chosen to be incorporated in biodegradable films based on cassava starch because it was more efficient against Penicillium commune and Eurotium amstelodami. Antimicrobial activity of biodegradable films with cinnamon essential oil was evaluated by means of a halo diffusion test in which an inhibition zone around a sample of the biodegradable and active film was analysed. As alternative method of antimicrobial agent incorporation, carbon dioxide (CO2) in supercritical state was used as solvent. Promising results were obtained since the amount of antimicrobial agent incorporated inside the polymeric matrix was sufficient to inhibit proliferation of fungi.

A embalagem desempenha uma função crucial na estabilidade dos alimentos. Neste estudo avaliou-se a estabilidade microbiológica de néctar de jabuticaba e caldo de cana pasteurizados (85 ºC/30 s), acondicionados assepticamente em garrafa de polietileno de alta densidade (PEAD) incorporada com agentes inorgânicos microestruturados com Ag/ZnO. Os lotes processados foram estocados a 5 ºC na ausência de luz. Testes físico-químicos, microbiológicos e sensoriais foram conduzidos para avaliar a estabilidade e estimar o tempo de vida útil das bebidas. Médias de notas superiores a 5 (na escala hedônica de 9 pontos) e percentagens de aceitação superiores a 60% foram estabelecidas para estimar o tempo de vida de prateleira das bebidas. Os resultados dos testes físico-químicos para o néctar de jabuticaba variaram de 3,40 a 3,76 para o pH, de 11,0 a 12,5 ºBrix para sólidos solúveis totais, e de 0,52 a 0,76% (m/m) de ácido cítrico para acidez total titulável. Para o caldo de cana, os valores de pH, sólidos solúveis totais e acidez total titulável variaram de 5,10 a 5,37; 14,3 a 24,0 ºBrix e de 0,05 a 0,13%(m/m) ácido cítrico, respectivamente, durante o período do estudo. Para o néctar de jabuticaba, as contagens de mesófilos, psicrotróficos e bolores e leveduras variaram de 1 a 1,5; &lt; 1est a 1; &lt; 1est a 1,3 logUFC/mL respectivamente, durante o período de estocagem. Para o caldo de cana as contagens variaram de &lt; 1est a 4,5 1est a 4,4; 1est a 4,0 logUFC/mL. O néctar de jabuticaba alcançou maior estabilidade microbiológica que o caldo de cana. As médias de notas para sabor, aparência e impressão global obtidas nos testes de escala hedônica variaram entre 6 a 7,1 para o néctar de jabuticaba e 5 e 7,7 para o caldo de cana. O néctar de jabuticaba e caldo de cana permaneceram microbiologicamente estáveis por um período de 120 e 50 dias, respectivamente. Os agentes inorgânicos microestruturados com Ag/ZnO não exerceram influência na estabilidade microbiológica dos dois produtos. / Packaging plays a crucial role in food stability. In this study, the microbiological stability of pasteurized (85 ºC/30 s) jabuticaba nectar and cane juice, aseptically packaged in high density polyethylene (HDPE) bottle treated with silver and zinc oxide (Ag/ZnO), was evaluated. All processed batches were stored at 5 ºC in the dark. Physicochemical, microbiological and sensory tests were conducted to evaluate the stability and estimate the beverage´s shelf life. Average scores greater than 5 (in the 9-point hedonic scale) and percentage of approval greater than 60% were both used as threshold values for estimating the product´s shelf life. As for the nectar, the pH ranged from 3.40 to 3.76; soluble solids from 11.0 to 12.5 ºBrix and titratable total acidity from 0.52 to 0.76% (w/w) citric acid. The pH values, total soluble solids and titratable acidity of cane juice varied from 5.10 to 5.37; 14.3 to 24.0 ºBrix and 0.05 to 0.13%(w/w) citric acid, respectively, during the storage. For nectar, counts of mesophiles, psychrotrophs and molds and yeasts ranged from 1 to 1.5; &lt; 1est to 1; &lt; 1est to 1.3 logCFU/mL, respectively, during the storage period. For the cane juice the counts ranged from &lt; 1est to 4.5; &lt;1est to 4.4; &lt;1est to 4.0 logCFU/mL. Jabuticaba nectar achieved longer microbiological stability than cane juice. The mean scores for flavor, appearance and overall impression obtained in the nine-point hedonic scale tests ranged from 6 to 7.1 for jabuticaba nectar and 5 and 7.7 for cane juice. Nectar and cane juice remained microbiologically stable for 120 and 50 days, respectively. The Ag/ZnO microstructured inorganic agents had no influence on the microbiological stability of both products.

O papel cartão é altamente higroscópico e poroso, influenciando nas propriedades mecânicas e de barreira e limitando sua utilização. Polímeros naturais, como quitosana (QUI) e gelatina (GEL) apresentam potencial para revestir papel cartão, possibilitando aumento da resistência e propriedades de barreira. Estes revestimentos têm capacidade de carregar compostos ativos naturais, tornando esse material uma embalagem ativa. Extratos de própolis e cúrcuma têm chamado a atenção na área alimentícia, porque apresentam propriedades antioxidantes e antimicrobianas. Assim, o objetivo deste trabalho foi desenvolver um novo sistema: papel cartão revestido com QUI e GEL para embalagem de alimentos susceptíveis a oxidação lipídica e/ou degradação microbiana utilizando-se extratos etanólicos de própolis (EEP) e cúrcuma (EEC). Os extratos foram produzidos com relação de 3:10 de própolis ou cúrcuma:etanol 80 %. Foi determinada a concentração e estabilidade dos compostos fenólicos totais, atividade antioxidante e antimicrobiana dos extratos. O papel cartão foi revestido com uma camada de diferentes soluções de QUI e GEL, utilizando as relação de QUI:GEL igual a 100:0 80:20, 60:40, 40:60, 20:80, 0:100 (formando os sistema filme-papel cartão-SF-PC). Os SF-PC foram caracterizados quanto à análise visual, homogeneidade do revestimento (HOM), análise microestrutural, gramatura (GRA), espessura, resistência ao estouro, teste de tração, permeabilidade ao ar, rugosidade, permeabilidade à gordura (PG), permeabilidade ao vapor de água (PVA), capacidade de absorção de água (Cabs), conteúdo de água (CA), ângulo de contato e energia de superfície. O sistema filme-papel cartão-aditivado (SFPC-A) com EEP e EEC foram desenvolvidos com a relação de QUI:GEL otimizada. O SF-PC-A foi revestido com uma, duas e três camadas de solução e caracterizado em relação à análise visual, parâmetros de cor, HOM, análise microestrutural, GRA, espessura, rigidez Taber, PG, PVA, Cabs, CA e atividade antimicrobiana. A estabilidade dos compostos ativos dos SF-PC-A foi determinada por um período de 42 dias quanto à concentração de compostos fenólicos totais (CFT) e capacidade antioxidante pelo método do sequestro do radical livre DPPHo. O EEP apresentou maior CFT, atividade antioxidante e antimicrobiana em relação ao EEC. O SF-PC com blendas apresentaramse mais homogêneos que os revestimentos somente com QUI ou GEL. O aumento de GEL na solução de revestimento aplicado sobre o papel cartão provocou redução da barreira ao vapor de água e aumento da Cabs dos SF-PC. O revestimento com relação de 80QUI:20GEL apresentou ser o mais adequado para o desenvolvimento do SF-PC-A. Observou-se tendência de formar um filme contínuo sobre as fibras de celulose para os SF-PC-A com EEC e EEP em função do aumento do número de camadas e a espessura e GRA dos SF-PC-A aumentaram estatisticamente em relação a camada adicionada. A PVA aumentou significativamente para o SF-PC-A sem extrato e reduziu para o SF-PC-A com EEP. Não foi observada atividade antimicrobiana para ambos os papéis aditivados com EEP e EEC contra as bactérias testadas. Entretanto, os SF-PC-A com EEC e EEP apresentaram atividade antioxidantes durante 42 dias de armazenamento e os sistemas aditivados com EEP e EEC apresentaram maior atividade antioxidante com três camadas de revestimento quanto àquele com uma camada. Pode-se concluir que o novo sistema desenvolvido com adição de extratos naturais apresentou capacidade de utilização em alimentos como produtos cárneos embutidos, produtos frios fatiados, onde o antioxidante atuaria na redução da oxidação lipídica, podendo atuar no aumento de vida útil do produto. / Paperboard is highly hygroscopic and porous, which influences mechanical and barrier properties. Natural polymers, such as chitosan (CH) and gelatin (GE) are suitable to be used as a coating on paperboard, providing more flexibility and barrier properties to the material. These coatings have the ability to carry natural active compounds, making this material an active packaging. Propolis and curcuma extracts have attracted attention in the food area, because of their antioxidant and antimicrobial properties. Thus, the objective of this work was to develop a new system: paperboard coated with CH and GE to pack food susceptible to lipid oxidation and/or microbial degradation, using ethanolic propolis extract (EPE) and ethanolic curcuma extract (ECE). The extracts were produced with 3:10 propolis or curcuma:ethanol 80%. The total phenolic compound contents and stability, as well as the antioxidant and antimicrobial activity of extracts were determined. The paperboard was coated with one layer of different solutions of CH and GE, with proportional relations of CH:GE 100:0, 80:20, 60:40, 40:60, 20:80, 0:100 (forming the paperboard film system - PFS). The PFS was characterized regarding visual analysis, coating homogeneity, microstructural analysis, grammage, thickness, burst index, traction test, air permeability, roughness, fat permeability, water vapor permeability (WVP), water absorption capacity (WAC), moisture content (MC), contact angle and surface energy. The paperboard film additivated system (PFAS) with EPE and ECE were developed with CH:GE optimized ratio. The PFAS was coated with one, two, and three layers and characterized according to visual analysis, color parameters, coating homogeneity, microstructural analysis, grammage, thickness, Taber stiffness, fat permeability, WVP, WAC, MC and antimicrobial activity. Active compounds stability of PFAS was determined within a period of 42 days of storage by total phenolic compound contents and antioxidant capacity (DPPHo free radical scavenging method). EPE showed higher total phenolic compound contents, antioxidant and antimicrobial activity in relation to ECE. The PFS with CH:GE blends were more homogeneous than CH or GE coating. The increase of GE in the coating solution applied to the paperboard reduced WVP and increased the WAC of PFS. The 80CH:20GE coating ratio presented as the most suitable for the development of PFAS. A tendency to form a continuous film on the cellulose fibers for the PFSA with ECE and EPE was observed by the increase in the number of coating layers. PFAS grammage and thickness increased statistically by the added layer. WVP significantly increased for PFAS without extract and reduced for PFAS with EPE. Antimicrobial activity was not observed for both paperboards added with EPE and ECE against the bacteria tested. Antimicrobial activity was not observed for both paperboards added with EPE and ECE against the bacteria tested. However, PFAS with ECE and EPE presented antioxidant activity and in 42 days of storage. The three-layer systems showed higher antioxidant activity than those with one layer. It can be concluded that the new system developed with the addition of natural extracts showed the ability to be used in foods such as meat products and sliced cold products, where the antioxidant would reduce lipid oxidation and increase product shelf life.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2018-01-31T22:05:14Z No. of bitstreams: 1 Calila Teixeira Santos-Tese.pdf: 4768163 bytes, checksum: d983e00648de308f628e91544b43f14c (MD5) / Made available in DSpace on 2018-01-31T22:05:14Z (GMT). No. of bitstreams: 1 Calila Teixeira Santos-Tese.pdf: 4768163 bytes, checksum: d983e00648de308f628e91544b43f14c (MD5) Previous issue date: 2017-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The present study had as main objective to obtain bioactive extracts of the fruits of Schinus terebinthifolius Raddi (STF), with antioxidant and antimicrobial action, for incorporation in a bioactive package for foods, besides inhibition of acetylcholinesterase. The extraction process performed by focussed microwave (EAMF) and ultrasound (UAE). The comparison between extraction methods was monitored by the biological activities of these extracts. The results showed that for the yield there was no significant difference. For the EAMF assays, the best value of phenolic (5950 ? 1.4 mgGAE / g) and total flavonoids (1750 ? 3.2 mgEQ / g) was at the extraction time of 25 minutes at 51 ? C and with 75% ethanol. For the assays obtained by EAU, the best total phenolic content was (92.2 ? 0.8 mgGAE / g) in the EAU 10 test (extraction time of 30 minutes at 42 ? C and 50% ethanol) And flavonoids (67.72 ? 1.0 mgEQ / g) in the UAE 12 assay (extraction time of 17.5 minutes at 60 ? C and 50% ethanol). The best values for percent inhibition (% SRL) were 87.3% (EAMF 8) and 31.3% (UAE 12). Mass spectrometry analysis showed the presence of phenolic compounds and terpenes. In relation to the antimicrobial activity of extracts obtained by EAMF, the MIC for S. aureus was 0.5 mg / ml for E. coli 0.25 mg / ml, whereas the extract of EAU presented MIC of 0.5 mg / Ml for the two microorganisms analyzed. In the phytochemical study, it was possible to isolate 7 substances: agasthiflavone, tetrahydrorobustaflavone, masticadienoic acid (Z), masticadienoic acid (E), schinol, gallic acid and squalene, as well as a mixture with unsaturated fatty acid profile and a mixture with trisaccharide characteristics. Their chemical structures being determined by spectrophotometric methods such as 1H and 13C NMR, UV and MS. Two of the 17 EAMF extracts were selected, which were incorporated into an active high-methoxylation pectin-based film called "Extract 2" and "Extract 8" in various concentrations (0, 1, 3 and 5%). The films had a mean thickness of 0.007 mm for all concentrations of the extracts tested. It was observed in relation to the mechanical properties that there was an interaction of the polyphenolic components of the extracts with the materials used in the production of the films. The films were more permeable to water vapor (6.18-7.80 g.mm/m2.h.kPa) than the control film (5.12 g.mm/m2.h.kPa). The films of both extracts showed good thermal stability independent of the concentration tested. The films produced in this study presented antioxidant activity, and the films added from extract 8 presented the best% SRL values (54.45 and 67.08, respectively). All films obtained inhibition halo against the microorganisms tested. In view of the results, it can be inferred that FTS have antioxidant potential, antimicrobial activity and high inhibition of acetylcholinesterase and can be used in cosmetics, nutraceuticals and food industry, as well as a promising alternative in the production of active films. / O presente estudo teve como objetivo principal obter extratos bioativos dos frutos de Schinus terebinthifolius Raddi (STF), com a??o antioxidante e antimicrobiana, para incorpora??o em uma embalagem bioativa para alimentos, al?m de inibi??o da acetilcolinesterase. O processo de extra??o foi realizado por micro-ondas focalizado (EAMF) e ultrassom (EAU). A compara??o entre os m?todos de extra??o foi monitorada pelas atividades biol?gicas desses extratos. Os resultados mostraram que para o rendimento n?o teve diferen?a significativa. Para os ensaios de EAMF o melhor valor de fen?lico (5950 ? 1,4 mgGAE/g) e flavonoides totais (1750 ? 3,2 mgEQ/g) foi no tempo de extra??o de 25 minutos, na temperatura de 51 ?C e com 75% de etanol. Para os ensaios obtidos por EAU o melhor teor de fen?licos totais foi (92,2 ? 0,8 mgGAE /g) no ensaio EAU 10 (tempo de extra??o de 30 minutos, na temperatura de 42 ?C e com 50% de etanol) e de flavonoides (67,72 ? 1,0 mgEQ /g) no ensaio EAU 12(tempo de extra??o de 17,5 minutos, na temperatura de 60 ?C e com 50% de etanol). Os melhores valores para a percentagem de inibi??o (%SRL) foi de 87,3% (EAMF 8) e 31,3% (EAU 12). A an?lise por espectrometria de massa mostrou a presen?a de compostos fen?licos e terpenos. Em rela??o ? atividade antimicrobiana dos extratos obtidos por EAMF, a CIM para S. aureus foi de 0,5 mg/ml, para E. coli 0,25 mg/ml, enquanto que o extrato de EAU apresentou CIM de 0,5 mg/ml para os dois microrganismos analisados. No estudo fitoqu?mico foi poss?vel isolar 7 subst?ncias: agasthiflavona, tetrahidrorobustaflavona, ?cido masticadienoico (Z), ?cido masticadienoico (E), schinol, ?cido g?lico e o esqualeno, al?m de uma mistura com perfil de ?cidos graxos insaturados e uma mistura com caracter?stica de trissacar?deos. Sendo suas estruturas qu?micas determinadas por m?todos espectrom?tricos tais como RMN 1H e 13C, UV e EM. Selecionou-se 2 dos 17 extratos EAMF, os mesmos foram incorporados em um filme ativo, ? base de pectina de alta metoxila??o, denominados ?Extrato 2? e ?Extrato 8? em concentra??es diversas (0, 1, 3 e 5%). Os filmes apresentaram espessura m?dias de 0,007 mm para todas as concentra??es dos extratos testados. Observou-se em rela??o as propriedades mec?nicas que houve uma intera??o dos componentes polifen?licos dos extratos com os materiais utilizados na produ??o dos filmes. Os filmes foram mais perme?veis ao vapor d??gua (6,18?7,80 g.mm/m2.h.kPa) do que o filme controle (5,12 g.mm/m2.h.kPa). Os filmes de ambos extratos mostraram uma boa estabilidade t?rmica independente da concentra??o testada. Os filmes produzidos neste estudo apresentaram atividade antioxidante, sendo que os filmes adicionados do extrato 8 apresentaram os melhores valores de %SRL (54,45 e 67,08, respectivamente). Todos os filmes obtiveram halo de inibi??o contra os micro-organismo testados. Diante dos resultados encontrados pode-se inferir que os STF t?m potencial antioxidante, atividade antimicrobiana e alta inibi??o de acetilcolinesterase podendo ser utilizados em cosm?ticos, produtos nutrac?uticos e na ind?stria alimentar, al?m de uma alternativa promissora na produ??o de filmes ativos.