Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2016-03-04T12:22:40Z No. of bitstreams: 1 arquivototal.pdf: 1248190 bytes, checksum: d7450bed1df69cfbbfdfea7c68d7863b (MD5) / Made available in DSpace on 2016-03-04T12:22:40Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1248190 bytes, checksum: d7450bed1df69cfbbfdfea7c68d7863b (MD5) Previous issue date: 2015-03-03 / Coalho cheese is obtained by enzymatic coagulation by the action of renin or specific enzymes, as well as using starter lactic acid bacteria (LAB) cultures that positively contribute to organoleptic aspects of the product. Some physicochemical characteristics of this cheese, as high moisture and pH, favor the growth of pathogenic bacteria frequently associated to outbreaks, such as Staphylococcus aureus and Listeria monocytogenes. The development of these pathogens in coalho cheese could be avoided by the adding of synthetic additives, however the growing interest of consumers for natural foods, free or containing low levels of chemical additives, have led the research of natural compounds with antimicrobial properties that can be used in food industry. The essential oil from Thymus vulgaris L. (TVEO), popularly known as thyme, possesses recognized antimicrobial activity against pathogenic bacteria, however there is no information about its effect on bacteria of technological interest, such as starter lactic acid cultures, used cheese manufacture. Considering these aspects, this study was performed to evaluate the inhibitory effect of TVEO on Lactococcus strains commonly used in coalho cheese processing as well as on pathogenic strains S. aureus and L. monocytogenes. For this, the values of minimum inhibitory concentration (MIC) of TVEO were determined against the test strains and the effects of TVEO on bacterial cell viability were assessed in cheese-based broth and in cheese samples. The main constituents of TVEO identified by CG-MS, were thymol (43.19%) and p-cymene (28.55%). The MIC value MIC of TVEO was 2.5 μL/mL against S. aureus and L. monocytogenes, and 1.25 μL/mL against L. lactis subsp. lactis and L. lactis subsp. cremoris in co-culture. In the assays in cheese-based broth containing TVEO at 1.25 μL/mL after 24 h, a decrease of approximately 1 log CFU/mL in the viable cell counts of L. monocytogenes and Lactococcus spp. was observed. At the same concentration, the TVEO presented no inhibitory effects on the growth of S. aureus. Only when TVEO was incorporated in growth media at 5 μL/mL viable cell counts of S. aureus and L. monocytogenes presented a sharp decrease over time, showing kill-time curves shape similar to that obtained when starter co-culture was exposed to TVEO at 2.5 μL/mL. TVEO at 5 μL/mL decrease 2 log CFU/mL the viable cell counts of the starter co-culture after 12 h of exposure. In the assays with coalho cheese added of TVEO at 1.25 μL/g no reduction in viable cells counts of co-culture or pathogenic bacteria was observed. However, OETV at 2.5 μL/g caused a decrease in viable cell counts of all tested bacteria tested after 72 h of exposure, varying from 0.3 to 1.0 log CFU/g. The results suggest that TVEO concentrations required to control pathogenic bacteria in coalho cheese should be carefully considered, since they can have negative effects on the growth and survival of lactic bacteria of the lactic fermentum. / O queijo de coalho é obtido por coagulação enzimática através da ação da renina ou enzimas específicas, assim como pelo uso de culturas de bactérias ácido-lácticas (BAL) iniciadoras, que contribuem positivamente para os aspectos organolépticos deste produto. Algumas características físico-químicas desse tipo de queijo, como elevada umidade e pH, favorecem o crescimento de bactérias patogênicas, frequentemente associadas a surtos alimentares, como Staphylococcus aureus e Listeria monocytogenes. O desenvolvimento destes patógenos no queijo coalho pode ser evitado pela adição de antimicrobianos sintéticos; entretanto, o crescente interesse dos consumidores por alimentos mais naturais, livres ou com baixos níveis de aditivos químicos, tem direcionado as pesquisas sobre compostos naturais com propriedades antimicrobianas que possam ser usados na indústria de alimentos. O óleo essencial de Thymus vulgaris L. (OETV), popularmente conhecido como tomilho, tem atividade antimicrobiana reconhecida contra bactérias patogênicas, porém não existem informações sobre seu efeito sobre bactérias de interesse tecnológico, como culturas lácticas iniciadoras, utilizadas no processamento de queijos. Considerando tais aspectos, o presente estudo foi desenvolvido com o objetivo de avaliar o efeito inibitório do OETV sobre cepas de Lactococcus frequentemente utilizadas no processamento de queijo de coalho, bem como sobre cepas das bactérias patogênicas S. aureus e L. monocytogenes. Para isso, foram determinados os valores da concentração inibitória mínima (CIM) do OETV, e os efeitos do OETV sobre a viabilidade das células bacterianas foram determinados em caldo base-queijo e em amostras de queijo de coalho. Os principais constituintes do OETV, identificados por CG-MS, foram timol (43,19%) e p-cimeno (28,55%). O valor da CIM de OETV foi de 2,5 μL/mL frente a S. aureus e L. monocytogenes, e de 1,25 μL/mL contra a L. lactis subsp. lactis e L. lactis subsp. cremoris em co-cultura. Nos ensaios em caldo base-queijo contendo OETV na concentração de 1,25 μL/mL, após 24 h, foi observada uma queda de aproximadamente 1 log UFC/mL nas contagens de células viáveis de L. monocytogenes e de Lactococcus spp. Na mesma concentração, o OETV não apresentou efeito inibitório sobre o crescimento de S. aureus. Somente nos ensaios com o OETV a 5 μL/mL, a contagem de células viáveis de S. aureus e L. monocytogenes apresentou um decréscimo acentuado ao longo do tempo, com as curvas de tempo de morte semelhante àquela obtida para a co-cultura láctea quando exposta ao OETV a 2,5 μL/mL. O OETV a 5 μL/mL provocou uma forte diminuição no número de células viáveis da co-cultura láctica, com contagens de 2 log UFC/mL após 12 h de exposição. Nos ensaios com o queijo de coalho adicionado de OETV a 1,25 μL/g não houve redução na contagem de células viáveis da co-cultura láctica ou das bactérias patogênicas ensaiadas. Porém, a concentração 2,5 μL/g, o OETV provocou uma redução na contagem de células viáveis de todas as bactérias ensaiadas ao longo de 72h de exposição, que variou de 0,3-1,0 log UFC/g. Os resultados sugerem que as concentrações de OETV necessárias para controlar bactérias patogênicas em queijo de coalho devem ser cuidadosamente consideradas, pois podem apresentar efeitos negativos sobre o crescimento e sobrevivência das bactérias que compõem o fermento láctico.

A oxidação de lipídeos produz compostos indesejáveis que alteram as características organolépticas de alimentos lipídicos e reduzem a qualidade nutricional. Nas indústrias alimentícia, cosmética e farmacêutica são adicionados antioxidantes sintéticos para retardar ou prevenir a deterioração lipídica. Devido aos estudos sobre a possível toxicidade dos antioxidantes sintéticos e ao apelo por compostos ativos naturais, o uso de antioxidantes naturais presentes em ervas e especiarias representa uma alternativa promissora. No presente trabalho foram estudadas as condições de obtenção de extratos hidroalcoólicos de especiarias e sua aplicação em óleo de soja refinado em teste acelerado. O estudo do efeito da temperatura e do grau de hidratação do etanol sobre o teor de compostos fenólicos totais dos extratos de alecrim, orégano, sálvia e tomilho foi realizado com aplicação de planejamento experimental e metodologia de superfícies de resposta. As condições para uma extração eficiente dos compostos fenólicos de alecrim e tomilho desidratados foram o uso de etanol 50% (v/v) e temperatura entre 45 a 50°C. Extrato de sálvia com maiores concentrações em fenólicos totais foram obtidos com etanol 50% (v/v) em uma faixa de temperatura de 57,5 a 60°C. O extrato de orégano requer uso de etanol 40-50% (v/v), em qualquer temperatura na faixa estudada (30 a 60°C). Os compostos identificados por cromatografia gasosa acoplada à espectrometria de massas foram os ácidos cafeico e dihidrocafeico, timol e arbutina. Os extratos de alecrim, orégano e tomilho preparados nas condições otimizadas, bem como suas misturas binárias e ternárias, foram adicionados ao óleo de soja refinado e submetidos a teste acelerado em estufa a 60°C. Os resultados de Índice de Peróxido e Absortividade na faixa do ultravioleta evidenciaram que as misturas de extratos foram capazes de oferecer proteção antioxidante ao óleo de soja refinado. Combinações com alecrim apresentaram os melhores efeitos protetores, sendo a melhor combinação das proporções 15% de tomilho, 65% de alecrim e 20% de orégano, totalizando 100 mg de compostos fenólicos totais/g de óleo. / The lipid oxidation produces undesirable compounds that alter the organoleptic characteristics of food lipids and reduce the nutritional quality. In the food, cosmetics and pharmaceutical industries, synthetic antioxidants are added to retard or prevent the lipid deterioration. Due to the possible toxicity of synthetic antioxidants and the call for active natural compounds, the use of natural antioxidants present in herbs and spices is a promising alternative. Thus, this study evaluated the antioxidant activity of extracts of spices and their mixtures on refined soybean oil. The study of temperature and solvent mixture effects on the phenolic extraction from dried rosemary, oregano, sage and thyme was performed according to response surface methodology and mathematical models. The conditions for an efficient extraction of the phenolic compounds from rosemary and thyme were ethanol 50% at 45-50°C; from sage was ethanol 50% at a temperature range from 57.5 to 60°C, and from oregano was ethanol 40-50% at any temperature in the studied range (30- 60°C). The compounds identified by gas chromatography-mass spectrometry were dihydrocaffeic and caffeic acids, thymol and arbutin. Selected hydroalcoholic extracts of rosemary, oregano and thyme were added to soybean oil subjected to accelerated storage tests. Peroxide values and absorptivity at UV showed that mixtures of extracts were able to provide antioxidant protection to soybean oil. Mixtures with rosemary showed better protective effects than the others. The region of the surface response of the mixtures in which the best protection is offered lies in the proportions of rosemary from 0.50 to 0.80, 0.10 to 0.30 of oregano and thyme from 0.05 to 0.30, in a total of 100 mf GAE/g oil.

Management of rare and threatened species requires an understanding of processes limiting population establishment and growth. The Large blue butterfly Phengaris arion needs two other organisms, the Thyme plant Thymus serpyllum and the ant genus Myrmica, for the completion of its life cycle. The large blue butterfly is very rare in Sweden and also declining in Europe, and both the large blue and Myrmica are red-listed and in need of protection. Studies conducted in Great Britain have suggested that a lack of suitable habitat with the presence of the host plant thyme and Myrmica limits the distribution of the large blue. A good environment for the butterfly is thus a habitat where all three organisms can exist. To examine whether vegetation structure and abundance of Thymus serpyllum and Myrmica ants are good predictors of the presence of the large blue in Sweden, I investigated sites where the butterfly has been observed or reportedly gone extinct in the last five years. I studied one site in the region of Stockholm, five sites in the Uppsala region, and 10 sites on the island of Gotland. At each site, I recorded an abundance of thyme and its flowering status, the presence of shrubs, trees, and open vegetation, and any observations of the large blue.  Areas with the large blue tended to have a higher abundance of thyme plants and a higher percentage of thyme flowers in bloom during my visit than areas without the large blue. The difference in abundance of shrubs and trees between sites with and without the butterfly was small. Areas with the large blue also tended to have shrubs and trees compared to areas without the large blue. Because the study species are rare and endangered, the number of sites with current and past occurrence is limited, which complicates the statistical analysis of factors influencing its distribution. However, the results indicate the importance of a high abundance of the host plant for the occurrence of the large blue, but also that the host plant is much more common than the butterfly. Ants of the genus Myrmica were observed at only two of eight sites with observations of the large blue.  This suggests that the method used to detect Myrmica ants was not efficient, or that the large blue is not critically dependent on Myrmica ants in Sweden. To conclude, the remaining populations of the large blue should be monitored and measures to improve habitat quality should be considered at sites where it has gone extinct. We can try to reintroduce species in areas where the species has previously existed with strong populations of the thyme and the ant. Create a similar reintroduction as the success story of the large blue butterfly in Great Britain.

This doctoral presentation consists of the preparation of critical editions of eight orchestral works by J.B. McEwen: Symphony in A minor (1895-99), Viola Concerto (1901), Coronach (1903), The Demon Lover (1907-08), Grey Galloway (1908), Solway, A Symphony (1911), Hills 'o Heather (1918), and Where The Wild Thyme Blows (1936). In the absence of any monograph on McEwen there is a chapter which brings together for the first time the biographical information that can be culled from various sources; some, like the correspondence between Henry George Farmer and McEwen in the late 1940's, has never been discussed before. A separate chapter surveys the collection of McEwen manuscripts held at Glasgow University Library, its condition, the extent of it, and how it came to be housed there. There follows a discussion of each of the selected works from the point of view of the editorial issues relating to them and also some aspects of McEwen's stylistic development. It was important to McEwen that a composer spoke in his native voice through his music as is evident in a letter he wrote to H.G. Farmer in 1947(1). Discussion of this aspect of his expressive style is therefore helpful in understanding his development from the early Symphony in A minor of 1895-99 to his last orchestral work, Where The Wild Thyme Blows of 1936. Such a stylistic study is secondary to the main thrust of the thesis which is a critical edition, but it is necessary in order to fully understand the complex issues involved in making McEwen's last orchestral work performable. Where The Wild Thyme Blows was left incomplete and the present editor has made a performing version. There is a brief concluding section which consolidates evident features of the McEwen manuscripts which would be useful for further studies of these papers. Each of the selected works is presented as a separate volume in a scholarly edition with full critical commentary given at the end of each volume. (1) Glasgow University Library catalogue n.MS Farmer 217

Tesis por compendio / [ES] Esta memoria de tesis presenta una contribución al estudio de la funcionalización de sustratos textiles mediante la encapsulación de diferentes compuestos empleando la técnica del electrohilado. La variabilidad de la electrohilatura, tanto a nivel del equipo empleado como del propio proceso de electrohilado, permite la posibilidad de obtener morfologías y composiciones de nanofibras completamente distintas. En este trabajo se han abordado dos técnicas de preparación de la solución polimérica a emplear durante el proceso, los métodos de emulsión y dispersión. Ambas técnicas han posibilitado la adición de varios compuestos que han aportados nuevas características a nanofibras de PVA electrohiladas. Tras analizar los resultados obtenidos de las nanofibras extruidas a partir de la solución por emulsión, se ha demostrado la capacidad de encapsular aceites esenciales, tomillo y salvia, mediante electrohilatura. La caracterización realizada a los velos nanofibrosos demuestran la aparición de microcápsulas a lo largo de la sección longitudinal de las fibras debido a la encapsulación del aceite en su interior. Por otro lado, el método de dispersión ha sido evaluado mediante la adición de cúrcuma, compuesto no soluble en agua, a una solución de PVA. Los datos resultantes de las caracterizaciones han evidenciado la capacidad de la cúrcuma de actuar como sensor halocrómico aún estando encapsulada en el interior de las nanofibras electrohiladas. Al mismo tiempo, se ha examinado si esta capacidad halocrómica se mantiene cuando las nanofibras de PVA, que inicialmente son solubles en agua, se someten a un proceso de reticulación con ácido cítrico para su insolubilización. Los resultados han demostrado la continuidad del halocromismo, aunque difiere en la tonalidad del color resultante. Finalmente, se concluye con una comparativa por adición de materia colorante mediante los dos métodos explicados a una solución polimérica. Los velos nanofibrosos fabricados a partir de la solución dispersada presentaban una notable coloración en su superficie, mientras que las nanofibras producidas a partir de la solución por emulsión no presentaban color, lo cual vuelve a justificar la encapsulación del aceite coloreado en el interior de la nanofibra. / [CA] Aquesta memòria de tesi presenta una contribució a l'estudi de la funcionalització de substrats tèxtils mitjançant l'encapsulació de diferents compostos emprant la tècnica de l'electrofilat. La variabilitat de l'electrofilatura, tant a nivell de l'equip emprat com del procés d'electrofilat propi, permet la possibilitat d'obtenir morfologies i composicions de nanofibres completament diferents. En aquest treball s'han abordat dues tècniques de preparació de la solució polimèrica a emprar durant el procés, els mètodes d'emulsió i de dispersió. Ambdues tècniques han possibilitat l'addició de diversos compostos que han aportat noves característiques a nanofibres de PVA electrofilades. Després d'analitzar els resultats obtinguts de les nanofibres extruïdes a partir de la solució per emulsió, s'ha demostrat la capacitat d'encapsular olis essencials, farigola i sàlvia, mitjançant electrofil·latura. La caracterització realitzada a les estores nanofibroses demostren l'aparició de microcàpsules al llarg de la secció longitudinal de les fibres a causa de l'encapsulació de l'oli al seu interior. D'altra banda, el mètode de dispersió s'ha avaluat mitjançant l'addició de cúrcuma, compost no soluble en aigua, a una solució de PVA. Les dades resultants de les caracteritzacions han evidenciat la capacitat de la cúrcuma d'actuar com a sensor halocròmic encara estant encapsulada a l'interior de les nanofibres electrofilades. Alhora, s'ha examinat si aquesta capacitat halocròmica es manté quan les nanofibres de PVA, que inicialment són solubles en aigua, se sotmeten a un procés de reticulació amb àcid cítric per a la seua insolubilització. Els resultats han demostrat la continuïtat de l'halocromisme encara que difereix en la tonalitat del color resultant. Finalment, es conclou amb una comparativa per addició de matèria colorant mitjançant els dos mètodes explicats a una solució polimèrica. Els vels nanofibrosos fabricats a partir de la solució dispersada presentaven una notable coloració a la superfície, mentre que les nanofibres produïdes a partir de la solució per emulsió no presentaven color, la qual cosa torna a justificar l'encapsulació de l'oli acolorit a l'interior de la nanofibra. / [EN] This thesis report presents a contribution to the study of the functionalisation of textile substrates through the encapsulation of different compounds using the electrospinning technique. The variability of electrospinning, both at the level of the equipment used and of the electrospinning process itself, allows the possibility of obtaining completely different morphologies and compositions of nanofibres. In this work, two techniques for the preparation of the polymer solution to be used during the process have been addressed, the emulsion and dispersion methods. Both techniques have allowed the addition of several compounds that have provided new properties to electrospun PVA nanofibres. After analysing the results obtained from the nanofibres extruded from the emulsion solution, the ability to encapsulate essential oils, thyme and sage, by electrospinning was demonstrated. The characterisation of the nanofibrous mats shows the appearance of microcapsules along the longitudinal section of the fibres, due to the encapsulation of the oil inside them. On the other hand, the dispersion method was evaluated by adding turmeric, a non-water soluble compound, to a PVA solution. The data obtained from the characterisations have showed the ability of turmeric to act as a halochromic sensor even when encapsulated in the electrospun nanofibres. At the same time, it was investigaed whether this halochromic capacity is maintained when the PVA nanofibres, which are initially soluble in water, undergo a cross-linking process with citric acid to insolubilise them. The results have shown the continuity of the halochromism, although the resulting shade is different. Finally, we compare the addition of dyes to a polymer solution using the two methods described above. The nanofibrous veils produced from the dispersed solution showed a noticeable colouration on their surface, whereas the nanofibres produced from the emulsion solution were colourless, which again justifies the encapsulation of the coloured oil inside the nanofibre. / Mínguez García, D. (2024). Funcionalización de textiles mediante encapsulación por electrohilatura [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202719 / Compendio

[EN] Chitosan films and coatings have been obtained, by incorporating different essential oils (EO) and using different homogenization conditions of the film forming emulsions, in order to obtain antifungal materials for fruit preservation. The effect of oleic acid (OA) on the stability of the initial emulsions and on the film properties was analysed. Coatings were applied to control fungal decay in strawberries. The blending of chitosan with methylcellulose (MC) was also used in coating applications to tomato plants and fruits to prevent fungal infections. The films' functional properties as a function of their composition were analysed, as well as their antimicrobial activity through in vitro and in vivo tests. OA incorporation in the chitosan films (1:1 wt. ratio) reduced water vapour permeability (WVP) values to about 50 % of those of net chitosan films, with a small positive effect of the microfluidization process. EO (cinnamon, thyme and basil) did not notably reduced the WVP values of the chitosan films but a significant improvement in water barrier capacity was induced when OA was also added at 1:1 or 1:0.5 CH:OA ratios. In contrast, lipids slightly promoted oxygen permeability of the films. Lipid addition decreased the film stretchability and stiffness, with a lesser impact on the resistance to break, slightly depending on the droplet sizes. Essential oils also modulated the mechanical behaviour of the films, depending on their composition. Thyme and basil EO greatly promoted film stiffness and resistance to break, whereas cinnamon oil slightly reduced these mechanical attributes. Optical properties of the chitosan films were also affected by lipid incorporation. OA reduced the film transparency and gloss depending on the concentration, but provoked small changes in the colour parameters and whiteness index. EO affected transparency to a lesser extent, but had greater impact on the colour coordinates and whiteness index of the chitosan films due to the selective light absorption of their compounds. EO blend with oleic acid mitigated the colour changes in the films. Likewise, blending of OA with EO significantly reduced the losses of volatiles during the film formation due to the promotion of the stability of the film forming emulsions. Films containing cinnamon EO were effective in reducing the growth of Aspergillus niger, Botrytis cinerea and Rhizopus stolonifer, although thyme and basil EO encapsulated in the films did not exhibit antifungal action against these three fungi. When chitosan-cinnamon EO coatings were applied to strawberries inoculated with R. stolonifer, they reduced the fungal decay of the fruits during 14 days, at 10 °C, at the same time that total coliform counts were maintained at the initial levels. Chitosan coatings with lemon essential oil were also active at controlling fungal decay in strawberries. These did not significantly affect the physicochemical parameters of strawberries throughout cold storage, while they slowed down the respiration rate of the fruits and enhanced the chitosan antifungal activity against B. cinerea. The coatings, with and without lemon EO, affected the strawberry volatile profile, although it was only sensory appreciated for samples coated with chitosan-lemon oil. Blend films of CH and MC (1:1) containing oregano EO caused phytotoxic problems at "3 Leaves" stage of tomato plants, although the total biomass and crop yield was not affected. In the "Fruit" stage, the treatments had no negative effects. Coatings reduced the respiration rate of tomatoes, diminished weight loss during postharvest storage and were effective to decrease the fungal decay of tomatoes inoculated with R. stolonifer. Migration of thymol and carvacrol from CH-MC films in food simulants could overcome the stablished specific migration limit (60 mg/kg) for food contact packaging materials in aqueous and low pH systems if films contain a 1:1 polymer essential oil weight ratio. / [ES] En la presente tesis doctoral se han desarrollado diferentes materiales antifúngicos para su uso en conservación de frutas. Para ello, se han incorporado diferentes aceites esenciales (AE) en recubrimientos y películas de quitosano (Q). Se ha analizado el efecto de la adición de ácido oleico (AO) y las condiciones de homogeneización sobre la estabilidad de las emulsiones y sobre las propiedades de las películas. Se ha estudiado el efecto de los recubrimientos de Q sobre el deterioro fúngico en fresas y el efecto preventivo frente a infecciones fúngicas de las mezclas de metilcelulosa (MC) con Q en plantas de tomate. Se ha estudiado el efecto de la composición de las películas sobre las propiedades funcionales de las mismas, así como su actividad antimicrobiana in vitro e in vivo. La incorporación de AO en las películas de Q (proporción 1:1) redujo la permeabilidad al agua (PVA) en un 50% comparado con la de Q puro. La microfluidización indujo un efecto positivo sobre dicha reducción. La adición de AE (hoja de canela, tomillo o albahaca) no supuso una disminución notable de los valores de permeabilidad obtenidos para las películas de Q. Cuando se añadió AO a las formulaciones de Q y AE (proporciones 1:1 o 1:2), se promovió una mejora significativa en la PVA de las películas. En cambio, la adición de lípidos aumentó ligeramente la permeabilidad al oxígeno, disminuyó la elasticidad y la rigidez, y produjo un menor impacto sobre la resistencia a la rotura. A su vez, la adición de AE modificó el comportamiento mecánico de las películas. Los AE de tomillo y albahaca aumentaron considerablemente la rigidez y la resistencia a la rotura, mientras que el AE de hoja de canela redujo estos parámetros ligeramente. La adición de lípidos a las películas de Q afectó las propiedades ópticas de las mismas. El AO redujo la transparencia y el brillo, en función de la concentración añadida. La adición de AE tuvo un mayor impacto sobre los parámetros de color y el índice de blancura. Las mezclas de AE y AO mitigaron estos cambios de color. Además, la incorporación de las mezclas AE-OA redujo las pérdidas de volátiles del AE durante la formación de las películas. Las películas formuladas con el AE de hoja de canela fueron efectivas contra el crecimientos de A. niger, B. cinerea y R. stolonifer, aunque los AE de tomillo y albahaca encapsulados en las películas no mostraron ninguna actividad antifúngica. La aplicación de los diferentes recubrimientos de Q AE de C en fresas inoculadas con R. stolonifer dio lugar a una reducción en el deterioro fúngico de los frutos almacenados durante 14 días a 10°C. Los recubrimientos de Q-AE de limón también fueron efectivos en el control del deterioro fúngico en fresas. Estos recubrimientos no afectaron significativamente los parámetros físico-químicos de las fresas durante el almacenamiento en refrigeración, disminuyeron la tasa de respiración de los frutos y acentuaron la actividad antifúngica del Q frente a B. cinerea. Tanto los recubrimientos con AE como los de Q puro modificaron el perfil de volátiles de las fresas, aunque estos cambios solo fueron apreciados sensorialmente en el caso de los frutos recubiertos con AE. Las mezclas de Q y MC que contenían AE de orégano causaron efectos fitotóxicos en plantas de tomate en el estadio "3 hojas", aunque no afectaron a la biomasa total. En el estadio "frutos" los tratamientos no tuvieron ningún efecto negativo. Los recubrimientos redujeron la tasa de respiración de los tomates, disminuyeron la pérdida de peso durante el almacenamiento post-cosecha y fueron efectivos contra el deterioro fúngico de tomates inoculados con R. stolonifer. La migración de los compuestos fenólicos timol y carvacrol, contenidos en las películas de Q-MC, podría superar el límite de migración específica establecido (60 mg/Kg) para materiales de envase en contacto con alimentos en los casos de sistemas acuosos y d / [CAT] En la present tesi doctoral s'han desenvolupat diferents materials antifúngics per al seu ús en conservació de fruites. Per a açò, s'han incorporat diferents olis essencials (OE) en recobriments i pel·lícules de quitosano (Q). S'ha analitzat l'efecte de l'addició d'àcid oleic (AO) i les condicions d'homogeneïtzació sobre l'estabilitat de les emulsions i sobre les propietats de les pel·lícules obtingudes. S'ha estudiat l'efecte dels recobriments de Q sobre la deterioració fúngica en maduixes i l'efecte preventiu enfront d'infeccions fúngiques de les mescles de metilcelulosa (MC) amb Q en plantes de tomaca. S'ha estudiat l'efecte de la composició de les pel·lícules sobre les propietats funcionals de les mateixes, així com la seua activitat antimicrobiana in vitro i in vivo. La incorporació de AO en les pel·lícules de Q (1:1) va reduir la permeabilitat al vapor d'aigua (PVA) en un 50% comparat amb la de Q pur. La microfluidització va induir un petit efecte positiu sobre aquesta reducció. L'addició de AE (fulla de canyella, C, timó, T, i alfàbrega, A) no va suposar una disminució notable dels valors de permeabilitat obtinguts per a les pel·lícules de Q. Quan es va afegir AO a les formulacions de Q i AE, es va promoure una millora significativa en la PVA de les pel·lícules. Per contra, l'addició de lípids va augmentar lleugerament la permeabilitat a l'oxigen, va disminuir l'elasticitat i la rigidesa, i va produir un menor impacte sobre la resistència al trencament. Al seu torn, l'addició de OE va modificar el comportament mecànic de les pel·lícules. Els OE de T i d'A van augmentar considerablement la rigidesa i la resistència al trencament, mentre que l'OE de C va reduir aquests paràmetres lleugerament. L'addició de lípids a les pel·lícules de Q també va afectar les propietats òptiques de les mateixes. L'AO va reduir la transparència i la lluentor, en funció de la concentració afegida. L'addició d'OE va tenir un major impacte sobre el paràmetres de color i l'índex de blancor. Les mescles d'OE i AO van mitigar aquests canvis de color. A més, la incorporació de les mescles OE-AO va reduir les pèrdues de volàtils de l'OE durant la formació de les pel·lícules. Les pel·lícules formulades amb l'OE de C van ser efectives contra el creixements d'A. niger, B. cinerea i R. stolonifer, encara que els OE de T i A encapsulats en les pel·lícules no van mostrar cap activitat antifúngica. L'aplicació dels diferents recobriments de Q OE de fulla de canyella en maduixes inoculades amb R. stolonifer va donar lloc a una reducció en la deterioració fúngica dels fruits emmagatzemats durant 14 dies a 10°C. Els recobriments de Q-OE de llimó també van ser efectius en el control de la deterioració fúngica en maduixes. Aquests recobriments no van afectar significativament els paràmetres fisicoquímics de les maduixes durant l'emmagatzematge en refrigeració, van disminuir la taxa de respiració dels fruits i van accentuar l'activitat antifúngica del Q enfront de B. cinerea. Tant els recobriments amb OE com els de Q pur van modificar el perfil de volàtils de les maduixes, encara que aquests canvis sol van ser apreciats sensorialment en el cas dels fruits recoberts amb OE. Les mescles de Q:MC que contenien OE d'orenga van causar efectes fitotòxics en plantes de tomaca en l'estadi "3 fulles", encara que no van afectar a la biomassa total. En l'estadi "fruits" els tractaments no van tenir cap efecte negatiu. Els recobriments van reduir la taxa de respiració de les tomaques, van disminuir la pèrdua de pes durant l'emmagatzematge post collita i van ser efectius contra la deterioració fúngica de tomaques inoculades amb R. stolonifer. La migració dels compostos fenòlics timol i carvacrol, continguts en les pel·lícules de Q-MC, podria superar el límit de migració específica establit (60 mg/Kg) per a materials d'envàs en contacte amb aliments en els casos de sistemes aquosos i d / Perdones Montero, Á. (2015). ANTIFUNGAL CHITOSAN-BASED FILMS AND COATINGS CONTAINING ESSENTIAL OILS FOR FRUIT APPLICATIONS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59413 / TESIS