Os nanocristais são partículas de fármacos cristalinos, com tamanho médio na faixa de submicrons, geralmente entre 200 e 500 nm, estabilizados por agentes estéricos ou eletrostáticos adsorvidos na superfície das partículas do fármaco. Sua dimensão reduzida proporciona propriedades especiais, como a adesividade às mucosas e o aumento de área superficial e da solubilidade de saturação, o que melhora significativamente a biodisponibilidade de fármacos pouco solúveis em água. Outra aplicação emergente dos nanocristais é na melhoria da entrega e da retenção de fármacos em tecidos e células tumorais. Estudos demonstraram que o flubendazol é um fármaco capaz de induzir a morte celular em tumores malignos e retardar o seu crescimento, por meio da alteração que provoca na estrutura dos microtúbulos e pela inibição da polimerização da tubulina. Foi demonstrada sua atividade antiproliferativa em linhagens de leucemia, mieloma, câncer intestinal, câncer de mama e neuroblastoma. O flubendazol é também um fármaco eficaz contra os helmintos, demonstrando atividade superior na eliminação dos vermes adultos, quando comparado com a dietilcarbamazina. Embora o flubendazol pareça ser uma molécula promissora, é um fármaco praticamente insolúvel em água (0,005 mg/mL). Para atingir o efeito terapêutico desejado, é necessário o desenvolvimento de uma formulação com melhores solubilidade e biodisponibilidade. Nesse sentido, o presente trabalho apresenta o preparo e a caracterização físico-química de nanocristais de flubendazol por meio da microfluidização. Foram realizados ensaios exploratórios para avaliar a performance de diferentes agentes estabilizantes nas suspensões: o polissorbato 80, o polaxamer 188 e o D-α tocoferol polietilenoglicol 1.000 succinato (TPGS). A avaliação da distribuição do tamanho de partícula foi realizada por espalhamento de luz laser (LLS), espalhamento de luz dinâmica (DLS), análise de rastreamento de nanopartículas (NTA) e microscopia eletrônica de varredura (MEV). A utilização do TPGS favoreceu a obtenção de uma nanossuspensão com o menor diâmetro hidrodinâmico médio das partículas, de 253,9 ± 3,0 nm. Nos estudos exploratórios, também foram determinados os parâmetros ótimos de moagem do microfluidizador, sendo estabelecidos: 35.000 psi de pressão, temperatura do produto de 30°C (± 5°C) e tempo de recirculação de 2 horas/100 gramas. Objetivando alcançar o menor diâmetro hidrodinâmico médio dos nanocristais, executou-se um planejamento estatístico no qual foi avaliada a influência da concentração de flubendazol (% p/p) e de TPGS (% p/p) na formulação. A análise revelou a significativa influência da concentração do TPGS na redução do tamanho de partícula e na estabilidade físico-química da nanossuspensão. Ensaios complementares de solubilidade demonstraram que o nanocristal proporcionou incremento na solubilidade de 2,3 e 3,2 e 5,2 vezes em HCl 0,1 N, tampão fosfato pH 6,8 e tampão fosfato salino pH 7,4, respectivamente. No ensaio de dissolução conduzido em HCl 0,1 N e 0,1% TPGS, observou-se significativo incremento, de 41% de fármaco dissolvido após 60 minutos, quando comparado com o flubendazol micronizado. As características do estado sólido do nanocristal foram avaliadas por meio de análise térmica (calorimetria exploratória diferencial e termogravimetria) e difratometria de raios X, não sendo observadas significativas alterações da estrutura cristalina. O presente trabalho também avaliou a efetividade dos nanocristais de flubendazol em tumores de pulmão, demonstrando sua expressiva capacidade de retardar o crescimento e diminuir o tamanho desses tumores em camundongos xenotransplantados. / Nanocrystals are drug particles with an average size in the sub-micron range, generally between 200 and 500 nm, stabilized by steric or electrostatic agents adsorbed on the surface of the drug particles. The reduced size provides special properties such as mucosal adhesiveness, increase in surface area and saturation solubility, which significantly improves the bioavailability of poorly water-soluble drugs. Another emerging application of nanocrystals is in the enhancement of drug delivery and retention in tumor tissues. Studies have shown that flubendazole is a drug capable of inducing cell death in malignant tumors and decelerating their growth, by altering the structure of the microtubules and inhibiting the tubulin polymerization. Antiproliferative activity has been demonstrated in leukemia, myeloma, intestinal cancer, breast cancer and neuroblastoma lines. In addition, flubendazole is also an effective drug against helminths, demonstrating superior activity in eliminating adult worms when compared to diethylcarbamazine. Although flubendazole appears to be a promising molecule, it is an insoluble drug in water (0.005 mg / mL). To achieve the desired therapeutic effect, it is necessary the development of a formulation with better solubility and bioavailability. In this context, the present research reports the physico-chemical preparation and characterization of flubendazole nanocrystals through microfluidization. Exploratory experiments were carried out to evaluate the performance of different stabilizing agents in formulations: polysorbate 80, polaxamer 188 and D-α tocopherol polyethylene glycol 1000 succinate (TPGS). The determination of the particle size distribution determination was performed by laser light scattering (LLS), dynamic light scattering (DLS), nanoparticle scanning (NTA) and scanning electron microscopy (SEM). The use of TPGS favored the preparation of a nanosuspension with the lowest mean hydrodynamic size of the particles, of 253.9 ± 3 nm. In the exploratory studies, the optimum grinding parameters were also determined: 35,000 psi of microfluidizer pressure, product temperature of 30 ° C (± 5 ° C) and recirculation time of 2 hours for each 100 grams of suspension. In order to reach the lowest average hydrodynamic diameter, a statistical design was applied in which the influence of flubendazole concentration (% w / w) and TPGS (% w / w) on the formulation was evaluated. The analysis revealed a significant influence of TPGS concentration on the particle size reduction and on the physicochemical stability of the nanosuspension. Complementary solubility tests showed that the nanocrystal provided an increase in solubility of 2.3, 3.2 and 5.2-fold in 0.1 N HCl, phosphate buffer pH 6.8 and phosphate buffer saline pH 7.4, respectively. In the dissolution test performed in 0.1 N HCl with 0.1% TPGS, a 41% increase of the drug dissolved after 60 minutes was achieved, when compared to micronized flubendazole. The solid-state characteristics of the nanocrystal were accessed through thermal analysis (differential scanning calorimetry and thermogravimetry) and X-ray diffraction and the results indicated that the crystal structure was not significantly altered. This research also evaluated the action of flubendazole nanocrystals in lung tumors, demonstrating expressive ability to retard growth and decrease the size of these tumors in xenotransplanted mice.

Cellulose nanocrystals (CNCs) are bio-based nanoparticles with the ability to stabilize oil and water emulsions thanks to their intermediate wettability and nanometric size. These and other types of particle-stabilized emulsions, commonly referred to as Pickering emulsions, are of great academic and industrial interest due to their superior stability against drop coalescence compared to classical surfactant-stabilized emulsions. In addition, the presence of a densely packed layer of particles at the oil-water interface is expected to impact the encapsulation ability of the emulsion droplets opening up for the possibility to use these systems to modulate the release of active substances in the context of oral or topical delivery formulations used in pharmaceutical and cosmetic applications. In these types of applications, the use of emulsions with nano-sized drops is advantageous due to their longtermcolloidal stability, improved dermal and mucosal transport of actives, improved bioavailability and greater aesthetic appeal and skin feel. This study had two main objectives. The first one was to explore to possibility to produce o/w emulsions with submicron-size drops by means of microfluidization using a combination of CNCs and hydroxypropyl methylcellulose (HPMC), a surface-active cellulose derivative that has been shown to have the ability to modify the wettability of CNCs (thereby enhancing their ability to adsorb at the oil/water interface). An important aspect of this first part of the study also involved gaining better understanding on the separate contributions of CNCs and HPMC to the properties of the resulting emulsions. The second objective of the work was to assess the performance of selected o/w CNC/HPMC compared to that of surfactant-stabilised emulsions in terms of their ability to deliver lutein, a hydrophobic prototype active of interest for topical delivery applications. / Cellulosa-nanokristaller (CNC) är biobaserade nanopartiklar med förmågan att stabilisera emulsioner av olja i vatten (o/w) tack vare deras medelhöga vätbarhet och storlek i nanometerskalan. Dessa och andra typer av partikelstabiliserade emulsioner, så kallade Pickering-emulsioner, är av stort akademiskt och industriellt intresse på grund av deras överlägsna stabilitet mot droppkoalescens jämfört med klassiska tensidstabiliserade emulsioner. Det tätt packade skiktet av partiklar vid gränsytan mellan olja och vatten påverkar också inkapslingsförmågan hos emulsionsdropparna vilket kan utnyttjas för att reglera frisättning av aktiva substanser i läkemedel eller kosmetiska produkter. I dessa typer av applikationer är användningen av emulsioner med droppar i nano-storlek fördelaktig på grund av deras långsiktiga kolloidala stabilitet, förbättrad hud- och slemhinnetransport, förbättrad biotillgänglighet och hudkänsla. Denna studie hade två huvudmål. Det första var att undersöka möjligheten att producera o/w emulsioner med droppar av submikron-storlek med hjälp av mikrofluidisering och genom att använda en kombination av CNC och hydroxypropylmetylcellulosa (HPMC), ett ytaktivt cellulosa-derivat som har visat sig ha förmågan att modifiera vätbarheten hos CNC och därigenom förbättra dess förmåga att adsorbera vid olja/vatten-gränsytan. En viktig aspekt av denna första del av studien var att få bättre förståelse för hur CNC och HPMC var för sig påverkar egenskaperna hos emulsionerna. Det andra målet med arbetet var att bedöma prestandan hos o/w CNC/HPMC-emulsioner för frisättning av lutein, ett hydrofob aktivt ämne, och jämföra med tensidstabiliserade emulsioner. / nanocellulosa, hydroxipropylmetylcellulosa, Pickering emulsioner, microfluidization, drogleverans

Milk derived ingredients from the production of cheese and butter can be used as vehicles for nutrients. Buttermilk is a nutritious product of milk that comes from the churning of cream into butter. One of the advantages of buttermilk is that it is enriched in milk fat globule components, such as phospholipids and forms emulsions with fat when treated with high shear. The objective of this work was to explore the effects of shear on regular buttermilk and whey buttermilk in terms of liposomal aggregate size and chemical composition. The effects of microfluidization at 2000 psi and homogenization at 2000 psi/500 psi on the particle size distribution of liposomal aggregates between whey buttermilk (WBM) at pH 4.6 and 6.8 and commercial sweet buttermilk (SBM) at pH 4.60 were compared with whey protein isolate (WPI) at pH 4.6. At pH 6.80, WPI and SBM are too soluble in water to measure particle size but WBM is not as soluble. From this investigation, the mean particle diameter of the SBM aggregates at pH 4.6 decreased after the first pass through the microfluidizer and the same is true, after homogenization. SBM aggregates at pH 4.6 had a significantly larger mean particle diameter before treatments in both shear processes compared to WPI at pH 4.6 and WBM at pH 4.6 and WBM at pH 6.8 (p < 0.0001). WPI at pH 4.6 and WBM at both pH showed no significant differences in their mean particle size in both homogenized and microfluidized treatments. WPI and SBM samples resulted in significant particle diameter differences vi from before to after homogenizing at pH 4.6. SBM at pH 4.6 had significantly larger average particle diameter than WBM at pH 4.6 (p < 0.0002), WPI at pH 4.6 (p < 0.0002) and WBM at pH 6.8 (p < 0.0045) before microfluidization at pass 0. WBM and WPI across all treatments showed very similar tendencies in small particle size attributes and some similarities in protein composition. In addition, the small aggregate size of WBM is suggested to be influenced by the presence of phospholipids and thus, creating significantly smaller mean particles compared to SBM even before inducing high shear. In contrast, treated and untreated SBM differed from WBM in phospholipid composition in both homogenization and microfluidization techniques. WBM samples contained more phospholipids than SBM, whereas WPI samples contained very low concentrations of phospholipids. Through HPLC analysis, WPI, SBM, and WBM showed different profiling of the phospholipid classes. These differences may be due structural changes of the aggregates from shearing, initial thermal treatments or hydrophobic and/or protein-phospholipid interactions between the aggregates. SBM samples also exhibited different protein profiling than WBM and WPI samples. This study suggests that high shear and presence of phospholipids impact the size distribution of liposomal aggregates through structural alterations. The aggregates can be utilized as a novel ingredient and in the processing of dairy foods to deliver nutrition.

Lignocellulosic biomass is under extensive investigation as a bioethanol and bio-based materials feedstock. However, the complex structural and chemical mechanisms of lignocellulosic plant, which cause resistance to deconstruction during saccharification, require a pretreatment process. In this study, raw materials (corn bran, wheat bran and wheat straw) were selected because of their production and consumption in Turkey and also their accessibilities to be used as bioethanol source. Microfluidization pretreatment (high-pressure fluidization), which stands as a new approach for nano-cellulosic fibers production, was studied at 500 bar and 2000 bar to observe the qualitative and quantitative modifications in enzymatic hydrolysis depending on its effects on lignocellulosic structure. Optimum cellulase concentrations were determined for microfluidized samples as 4.5 U/g dry biomass for wheat bran, corn bran and 6.0 U/g dry biomass for wheat straw samples for the first 150 min interval. Effective usage of solid loads were found as 5.0 %, 2.5 %, and 7.5 % (dw/v) for wheat bran, wheat straw and corn bran, respectively. X-ray diffraction and SEM results of the microfluidized samples have indicated that the pretreatment has increased crystallinity index of all the samples and resulted in a scattered structure. Comparisons with other methods (softening, dilute-acid and lime pretreatments) have shown that microfluidization is advantageous over others by reducing the time required for enzymatic hydrolysis and thus can be a promising alternative pretreatment.

The aim of current research is to analyze the effect of microfluidization on the stability and some quality characteristics of orange juice with respect to treatment pressure and cycle. Orange juice was microfluidized with four different pressures (34, 69, 103 and 138 MPa) and three different cycles (1, 2 and 3) at 18 &plusmn / 2 0C. Physical and chemical properties of microfluidized juices were compared with non-microfluidized freshly squeezed orange juice. Microfluidization made orange juice brighter and decreased redness and yellowness. There was a huge difference between non-microfluidized juice and microfluidized juice in terms of particle size. Microfluidization decreased the volume weighted mean (VWM) of orange juice between 90 % and 97 %. The results of total phenol content and antioxidant activity experiments showed that treatment pressure affected them positively / however cycle had not a significant effect on total phenol content and antioxidant property of orange juice (p&lt / 0.05). Our current research also includes effect of microfluidization on stability of orange juice. The broken down of aggregated structure and reduction in particle size due to treatment were observed by the scanning electron and light microscopes. Therefore, it was observed that treated orange juice could be homogeneous and opaque for 14 days at 4 0C. Cloud stability of juice showed that both pressure and cycle had important effect on the cloud stability (p&lt / 0.05). Microfluidization made the juice very stable but increase in pressure and cycle resulted in less stable juice. It was also measured that pectin methyl esterase activity was increased due to treatment of microfluidization.

Cancer is the second leading cause of death in the United States and its onset is highly incident in the lungs, with very low long-term survival rates. Chemotherapy plays a significant role for lung cancer treatment, and pulmonary delivery may be a potential route for anticancer drug delivery to treat lung tumors. Coenzyme Q₁₀ (CoQ₁₀) is a poorly-water soluble compound that is being investigated for the treatment of carcinomas. In this work, we hypothesize that formulations of CoQ10 may be developed for pulmonary delivery with a satisfactory pharmacokinetic profile that will have the potential to improve a pharmacodynamic response when treating lung malignancies. The formulation design was to use a vibrating-mesh nebulizer to aerosolize aqueous dispersions of CoQ₁₀ stabilized by phospholipids physiologically found in the lungs. In the first study, a method was developed to measure the surface tension of liquids, a physicochemical property that has been shown to influence the aerosol output characteristics from vibrating-mesh nebulizers. Subsequently, this method was used, together with analysis of particle size distribution, zeta potential, and rheology, to further evaluate the factors influencing the capability of this nebulizer system to continuously and steadily aerosolize formulations of CoQ₁₀ prepared with high pressure homogenization. The aerosolization profile (nebulization performance and in vitro drug deposition of nebulized droplets) of formulations prepared with soybean lecithin, dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC) were evaluated. The rheological behavior of these dispersions was found to be the factor that may be indicative of the aerosolization output profile. Finally, the pulmonary deposition and systemic distribution of CoQ₁₀ prepared as DMPC, DPPC, and DSPC dispersions were investigated in vivo in mice. It was found that high drug amounts were deposited and retained in the mouse lungs for at least 48 hours post nebulization. Systemic distribution was not observed and deposition in the nasal cavity occurred at a lower scale than in the lungs. This body of work provides evidence that CoQ₁₀ may be successfully formulated as dispersions to be aerosolized using vibrating-mesh nebulizers and achieve high drug deposition in the lungs during inhalation. / text

Cancer is the second leading cause of death in the United States and its onset is highly incident in the lungs, with very low long-term survival rates. Chemotherapy plays a significant role for lung cancer treatment, and pulmonary delivery may be a potential route for anticancer drug delivery to treat lung tumors. Coenzyme Q₁₀ (CoQ₁₀) is a poorly-water soluble compound that is being investigated for the treatment of carcinomas. In this work, we hypothesize that formulations of CoQ10 may be developed for pulmonary delivery with a satisfactory pharmacokinetic profile that will have the potential to improve a pharmacodynamic response when treating lung malignancies. The formulation design was to use a vibrating-mesh nebulizer to aerosolize aqueous dispersions of CoQ₁₀ stabilized by phospholipids physiologically found in the lungs. In the first study, a method was developed to measure the surface tension of liquids, a physicochemical property that has been shown to influence the aerosol output characteristics from vibrating-mesh nebulizers. Subsequently, this method was used, together with analysis of particle size distribution, zeta potential, and rheology, to further evaluate the factors influencing the capability of this nebulizer system to continuously and steadily aerosolize formulations of CoQ₁₀ prepared with high pressure homogenization. The aerosolization profile (nebulization performance and in vitro drug deposition of nebulized droplets) of formulations prepared with soybean lecithin, dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC) were evaluated. The rheological behavior of these dispersions was found to be the factor that may be indicative of the aerosolization output profile. Finally, the pulmonary deposition and systemic distribution of CoQ₁₀ prepared as DMPC, DPPC, and DSPC dispersions were investigated in vivo in mice. It was found that high drug amounts were deposited and retained in the mouse lungs for at least 48 hours post nebulization. Systemic distribution was not observed and deposition in the nasal cavity occurred at a lower scale than in the lungs. This body of work provides evidence that CoQ₁₀ may be successfully formulated as dispersions to be aerosolized using vibrating-mesh nebulizers and achieve high drug deposition in the lungs during inhalation.

[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