Orientador: Carlos Raimundo Ferreira Grosso / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T15:38:52Z (GMT). No. of bitstreams: 1 Santos_AndreaBarbosa_D.pdf: 1408161 bytes, checksum: b337fedcba99a6ce63c76b73fbcea3f1 (MD5) Previous issue date: 2003 / Resumo: Neste trabalho a oleoresina de páprica oriunda de frutos maduros de pimentões (Capsicum annuum L.), foi encapsulada por processo de atomização, utilizando-se os agentes encapsulantes aglomerados porosos de grânulos de amido de arroz / gelatina e goma arábica. A extração da oleoresina encapsulada foi realizada em ultra-som durante cinco minutos em álcool etílico hidratado apresentando rendimentos de extração de 48,8 e 77,5% para os encapsulados em goma arábica, e aglomerados de amido/gelatina respectivamente. Os rendimentos em relação à retenção durante o processo de encapsulação, corrigidos pela deficiência do método de extração, foram de 100% para cápsulas de goma arábica e em torno de 89% para encapsulados de aglomerados porosos de grânulos de amido de arroz / gelatina, expressos em base úmida. A estabilidade da oleoresina livre e microencapsulada foi avaliada frente às diferentes condições de temperatura (- 18 °C; 25 ± 3°C; 50 °C) e ao efeito da luz, com parte das cápsulas sendo mantidas em ambiente sem iluminação. Em ambos ensaios cápsulas fabricadas com goma arábica apresentaram maior proteção a oleoresina de páprica quanto à perda da cor original. A morfologia da parede mostrou que a parede dos encapsulados de aglomerados porosos de grânulos de amido de arroz / gelatina apresentou porosidade e interstícios foram evidenciados na matriz individualmente e nos aglomerados; em relação as microcápsulas de goma arábica, observou-se parede contínua, sem rachaduras ou poros aparentes, mas apresentando concavidades na superfície provocadas pelo processo de secagem. A distribuição de tamanho das partículas foi unimodal, com tamanho médio de 16,0 mm para as cápsulas de goma arábica e 20,3 mm para os aglomerados porosos de grânulos de amido de arroz / gelatina. A funcionalidade das microcápsulas quanto à liberação do recheio, foi avaliada por adição a dois sistemas alimentícios, um contendo somente gel de gelatina incolor sem sabor e em outro, contendo proteína, gordura, carboidratos (bolo). A distribuição da cor foi homogênea em ambos os sistemas, ou seja, não foi verificado à formação de pontos de concentração de cor nos produtos. A avaliação sensorial foi realizada através do teste afetivo de aceitação em escala hedônica de nove pontos, em relação às formulações dos padrões de gel de gelatina e, de bolo isentas de microcápsulas e do teste de comparação da coloração pela escala estruturada mista. As notas obtidas foram altas para os dois produtos antes da ingestão, média na faixa de seis e sete para a gelatina contendo encapsulados dos aglomerados porosos de grânulos de amido de arroz/gelatina e de goma respectivamente, e média de sete e nove para os bolos / Abstract: In this study the resinous paprika oil obtained from ripe peppers (Capsicum annuum L.), was encapsulated by a spray drying process, in porous agglomerates of rice starch/gelatin and gum Arabic capsules. The process of extracting the encapsulated resinous oil was carried out by breaking the capsules by ultrasonication in a solvent (hydrated ethyl alcohol) for five minutes, showing yields of 48,8 and 77,5% when Arabic gum and starch/gelatin were used respectively. The yields during the encapsulation process with respect to the retention of resinous oil as compared to the amount added, corrected by extractions methods, was 100% for gum Arabic capsules and about 89% when starch granules were formed (wet base). The stabilities of the free and micro encapsulated resinous oils were evaluated under different temperature and light conditions (freezer - 18 °C; room temperature 25 ± 3°C; and 50°C). Exposing part of the capsules in a controlled illumination chamber and maintaining the other part in a chamber with no light tested the effect of light. In both trials (temperature and light), capsules produced with gum Arabic provided greater protection to the paprika resinous oil, with respect to loss of the original color. By morphological observations the porosity of the rice starch was apparent when this material was used as wall material, interstices being observed in the matrix both individually and when agglomerated. When gum Arabic was used as wall material, the walls of the capsules were continuous, with no apparent cracks or pores, although showing some indentations on the surface provoked by the drying process. The average size of the capsules was determined by measuring particle size, both presenting a unimodal distribution, with an average particle size of 16,0 mm for the gum Arabic capsules and 20,3 mm for the rice starch/gelatin. In order to determine the functionality of the microcapsules with respect to the liberation of the core material, the capsules were added to two food systems, a simple system containing non-colored gelatin with no added flavor, and a more complex system containing protein, fat and carbohydrate (cake mix). The color distribution was homogenous in both systems, no localized concentrations of color being noted in any of the products. A preference test with a nine point hedonic scale was used for the sensory evaluation of the gelatin formulations and the cakes, as compared to those containing no microcapsules. The scores for both products were high before tasting, in the range from 6 to 7 for the gelatin containing starch/gelatin and gum capsules respectively, and 7 and 9 for the cakes / Doutorado / Doutor em Alimentos e Nutrição

Licopeno, um pigmento natural considerado o mais potente antioxidante dentre os carotenoides, é oque tem maior incidência no soro humano. Seu consumo regular está relacionado principalmente com a prevenção do câncer de próstata. Porém, estudos também demonstram sua relação com a prevenção de câncer de pâncreas e bexiga, doenças cardiovasculares como a aterosclerose e doenças neurodegenerativas. Todavia, por ser altamente insaturado o licopeno é susceptível à degradação, sendo degradado na presença de luz, oxigênio e se exposto a altas temperaturas. A microencapsulação entra como uma alternativa para tentar garantir maior estabilidade a este carotenoide. A técnica de spray-chilling, por dispensar o emprego de altas temperaturas e solventes durante o processo de atomização, representa uma alternativa promissora na encapsulação do licopeno. Os objetivos deste trabalho foram encapsular uma solução oleosa de licopeno (10%) através da técnica de spray-chilling,utilizando gordura vegetal low trans como carreador, caracterizar as micropartículas obtidas e avaliar a biodisponibilidade do licopeno livre e encapsulado em ratos wistars. Foram formulados seis tratamentos, que diferiam pela concentração de solução comercial de licopeno, sendo T1 com 20%, T2 com 23,1%, T3 com 28,6%, T4 com 33,3%, T5 com 17,9% mais 10% de goma arábica e T6 com 19,2% mais 5% de carboximetilcelulose (CMC). As micropartículas obtidas destes tratamentos foram avaliadas quanto a tamanho e distribuição, morfologia por microscopia eletrônica de varredura (MEV), espectroscopia de infravermelho com transformadas de Fourier (FT-IR), difração de raios-X (DRX). A estabilidade do licopeno encapsulado foi avaliada em diferentes condições de armazenamento (sob vácuo, umidade relativa de 33%, temperatura de refrigeração e ambiente) e também foi determinada por meio de quantificações periódicas de licopeno, bem como através da análise análise da cor instrumental. A biodisponibilidade foi avaliada utilizando-se 68 animais divididos em grupos, para os quais se administrou por gavagem o licopeno livre e o encapsulado. O tamanho das micropartículas obtidas ficou em torno de 60-110 µm e a distribuição foi polidispersa, independente da concentração de licopeno. A microscopia revelou micropartículas esféricas, com superfície rugosa, com alguns poros e tamanhos variados. No FT-IR verificou-se que não houve formação de ligações distintas na solução oleosa de licopeno e nas amostras atomizadas. Nos difratogramas observou-se a presença da forma polimórfica β para o agente carreador e para as micropartículas. Na estabilidade a adição da goma arábica e o armazenamento sob temperatura de refrigeração e vácuo, foram as melhores condições para retardar a degradação do licopeno. Os resultados dos ensaios de biodisponibilidade foram inconclusivos. Desta forma, conclui-se que é possível encapsular licopeno através da técnica de spray-chilling, porém, para trabalhos futuros, seriam necessários aprimoramentos na técnica de encapsulação e/ou na formulação para conferir maior proteção ao carotenoide, bem como adequações na metodologia para determinação de sua biodisponibilidade, para obtenção de resultados conclusivos. / Lycopene, a natural pigment considered the most potent antioxidant among the carotenoids, it has the higher incidence in the human serum. Its regular consumption is mainly related with the prevention of prostate cancer. However, studies also show its relation to the prevention of pancreatic cancer and bladder cancer, cardiovascular diseases such as atherosclerosis and neurodegenerative diseases. However, by being highly unsaturated the lycopene is susceptible to degradation, being degraded in the presence of light, oxygen and if exposed to high temperatures. The microencapsulation comes like an alternative to ensuring higher stability for this carotenoid. The technique of spray-chilling represents a promising alternative to encapsulation of lycopene. The aims of this study were to encapsulate an oily solution of lycopene (10%) through of the technique of spray-chilling, using a low-trans fat as carrier, to characterize the obtained microparticles and to evaluate the bioavailability of lycopene free and encapsulated in Wistar rats. Six treatments were formulated, that differed by the content of oily solution of lycopene:T1 with 20%, T2 with 23.1%, T3 with 28.6%, T3 with 28.6%, T4 with 33.3%, T5 with 17.9% plus 10% of Arabic gum and T6 with 19.2% plus 5% of carboxymethylcellulose (CMC). The microparticles obtained from these treatments were evaluated for size and distribution, morphology by scanning electron microscopy (SEM), infrared spectroscopy with Fourier transform (FT-IR) and X-ray difraction (XRD). The stability of the lycopene encapsulated was evaluated by its periodic quantification at different storage conditions (vacuum, relative humidity of 33%, refrigeration temperature and environment temperature). Instrumental color, \"L\" and \"a\" parameters, also was measured. The bioavailability was evaluated using 68 animals, for which the free and lycopene encapsulated were administered by gavage. The size of microparticles obtained was around 60-110 µm and the distribution was polydisperse, independent of the concentration of lycopene. The microscopy revealed spherical microparticles, with rough surface, with some pores and varying sizes. In the FT-IR it was found that there was no formation of distinct bonds in oily solution of lycopeno and the atomized samples. In the diffraction patterns observed the presence of polymorphic form \"β\" for the carrier agent and microparticles. On the stability the addition of Arabic gum and the storage at refrigerator temperature under vacuum, were the best conditions to delay the degradation of lycopene. The results of bioavailability assays were inconclusive. As conclusion, it is possible to encapsulate lycopene using the technique of spray-chilling but to future works, would be required improvements in the technique of encapsulation and/or formulations to give more protection to the carotenoid, as well as adjustments in the methodology for determination of their bioavailability, in order to obtaining conclusive results.

Este trabalho teve como objetivo a utilização da tecnologia que emprega CO2 em estado supercrítico para estudar a formação de micropartículas de óleos essenciais encapsulados em polissacarídeos. O referido tema tem caráter inovador e inédito, já que a tecnologia supercrítica tem sido utilizada na formação e impregnação de partículas, principalmente de solutos sólidos, mas não tem sido aplicada na encapsulação de óleos essenciais. Os processos estudados, RESS (Rápida Expansão de uma Solução Supercrítica) ou o PGSS (Partículas de Soluções ou Suspensões em Gás Saturado) envolvem baixas temperaturas, possibilitando a não degradação de compostos voláteis e termossensíveis, tornando-os mais estáveis. Foram utilizados nesta pesquisa, polímeros que são, normalmente, utilizados no processo convencional de \"aroma em pó\". Mesmo sendo insolúveis ou parcialmente solúveis em CO2 supercrítico houve o intuito de aproveitar estudos comprovados de estabilidade de óleos essenciais encapsulados nestes materiais e ainda manter o custo do produto já que polissacarídeos tem, relativamente, baixo valor comercial, quando comparado aos polímeros que são empregados nos estudos que usam estes processos. Ensaios preliminares foram realizados com diferentes polímeros: Amido modificado, dextrina, maltodextrina e Purity Gum Ultra®, (gentilmente cedidos pela Corn Products, atual Ingredion Incorporated, Mogi Guaçu, SP, BR) no intuito de selecionar o material de parede mais apropriado para a microencapsulação do óleo essencial, representado pelo limoneno. Os resultados preliminares comprovaram que houve impregnação e possível microencapsulação do limoneno, observados e constatados através de análises de microscopia (óptica, eletrônica e de fluorescência confocal a laser) especialmente para Purity Gum Ultra®, a qual apresentou comportamento desejável como estabilidade da dispersão preliminar e morfologia, em comparação com os outros polissacarídeos testados (dextrina, amido modificado e maltodextrina). Os ensaios subsequentes (dimensionamento das partículas, microscopia eletrônica de varredura, microscopia confocal na presença de fluoresceína, estabilidade térmica e quantificação do teor de limoneno microencapsulado) determinaram definitivamente a eficiência da Purity Gum Ultra® como polímero mais apropriado como agente encapsulante, e com isso foi demonstrada a eficiência da técnica proposta para esta finalidade. Ainda, a técnica de microencapsulação empregada (PGSS) apresentou valores significativos na retenção do limoneno com até 86% quando a suspensão foi preparada utilizando etanol (EtOH) e lecitina de soja como surfactante, sendo um relevante indicativo de que o processo de microencapsulação via PGSS proporcionou eficiente retenção do limoneno, além de apresentar outras vantagens sobre os processos de microencapsulação convencionais utilizados na indústria de alimentos. O processo de microencapsulação que utiliza CO2 supercrítico é considerado como \"tecnologia limpa\", aliado a este solvente ser considerado abundante, barato e ambientalmente seguro. Neste estudo constatou-se que, além do emprego de baixa temperatura no processo (50 - 60º C), não houve necessidade do emprego de água na suspensão. / This study aimed to use the technology that employs CO2 in supercritical state to study the formation of microparticles encapsulated essential oils in polysaccharides. The supercritical technology has been used in impregnating particles, mostly of solid solutes, but has not been applied to the encapsulation of essential oils. The studied processes RESS (Rapid Expansion of a Supercritical Solution) or PGSS (Particles Solutions or Suspensions in Saturated Gas) involving low temperatures, not allowing degradation of volatile and polymers that are normally used in the conventional process of \"aroma powder\" were used in this study. Even though it is insoluble or partially soluble in supercritical CO2 proven in order to take advantage of the stability studies of encapsulated essential oils in these materials and still keep the cost of the product as polysaccharides have relatively low value when compared to the polymers that are employed in studies using these processes. Preliminary tests were performed with different polymers : modified starch, dextrin, maltodextrin and Purity Gum Ultra ®, ( kindly provided by Corn Products, Current Ingredion Incorporated, Mogi, SP, BR ) in order to select the most appropriate material for wall microencapsulation of essential oil, represented by limonene. Preliminary results showed that there was possible impregnation and microencapsulation of limonene, observed and recorded through analysis of microscopy (optical, electron and confocal) especially for Purity Gum Ultra ®, which showed desirable behavior such as dispersion and stability of primary morphology compared to other polysaccharides tested (dextrin, modified starch and maltodextrin). Subsequent tests (particle sizing, scanning electron microscopy, confocal microscopy in the presence of fluorescein, thermic stability and quantification of the limonene content microencapsulated definitely determined the efficiency of Purity Gum Ultra ® as the most appropriate polymer as agent encapsulating and it has been demonstrated the efficiency of the proposed technique for this purpose. The technique employed for microencapsulation (PGSS) showed significant amounts of limonene retention of up to 86% when the suspension was prepared using ethanol (EtOH) and soy lecithin as surfactant. Being indicative of a material that microencapsulation by PGSS provided efficient retention of limonene, besides other advantages over conventional microencapsulation processes used in the food industry. The microencapsulation process that uses CO2 supercritical is considered \"clean technology \" due to the low toxicity of CO2 besides this solvent is considered abundant, inexpensive and environmentally safe. In this study it was found that, in addition to using low temperature process ( 50 - 60º C ), there was no need for the use of water in suspension.

Foram produzidas micropartículas simbióticas com carreador de natureza lipídica, obtidas por spray chilling. Como materiais ativos foram utilizadas duas cepas de micro-organismos probióticos (L. acidophilus-LA e L. rhamnosus-LR), dois prebióticos (inulina e polidextrose) e gordura de palma e palmiste interesterificada. Estudou-se a resistência destes probióticos ao processo aplicado, o comportamento das micropartículas sólido lipídicas (MSLs) frente ao fluido gástrico e intestinal simulados e suas viabilidades durante 120 dias de armazenamento à -18, 7 e 22°C sob vácuo ou umidade relativa controlada. A caracterização morfológica, granulometria, análise térmica (DSC), atividade de água, espectroscopia na região do infravermelho (FTIR) e difração de raios-X (XRPD) foram estudados. Spray chilling configurou-se como processo adequado aos probióticos, devido à baixa perda de células viáveis durante a obtenção das micropartículas, sendo que não foi observado interferência da ausência, presença e do tipo de prebiótico. Foram obtidas MSLs esféricas com superfície relativamente uniforme, e com tamanho médio entre 62,4±2,8 a 69,6±5,1 µm, sendo que não houve diferença significativa entre as formulações. As análises de difração de raios-X indicaram que não ocorreram alterações polimórficas durante o armazenamento refrigerado das MSLs. Quanto à análise térmica pode-se dizer que a presença de probióticos e prebióticos praticamente não interferiu na alteração da temperatura de fusão para todas as formulações estudadas, que variou de 45,37°C a 47,58°C, inferindo-se a ausência de interações significativas entre os ingredientes microencapsulados e o carreador, ausência que foi reafirmada pelos espectros de infravermelho. A microencapsulação favoreceu a sobrevivência frente aos fluidos gástrico e intestinal simulados, e possibilitou a manutenção de células viáveis acima de 106 UFC por grama até 120 dias de armazenamento em umidade relativa controlada para a formulação com L. acidophilus e polidextrose, a qual foi influenciada pela atividade de água da partícula, que por sua vez foi afetada pela incorporação de prebióticos. Tendo em vista o potencial da MSLs desenvolvidas, estas foram incorporadas ao sorvete. Nesta matriz as micropartículas não apresentaram um bom desempenho, seja na sobrevivência de L. acidophilus durante o armazenamento do produto, como na proteção diante da exposição às condições gastrointestinais simuladas. Além disso, sorvetes com adição das MSLs foram avaliados com notas significativamente menores (p≤0,05) nos atributos textura, sabor e aceitação global em relação a amostras controle e a com adição de probióticos livres na análise sensorial do produto desenvolvido. As micropartículas lipídicas produzidas mostraram-se aptas como ingrediente alimentício, porém no sorvete não atenderam as premissas de proteção e extensão de contagens apropriadas do probiótico. As MSLs também foram incorporadas em polpas de fruta, abacate e melão, neste tipo de matriz as MSLs conferiram proteção ao micro-organismo pois aumentaram sua viabilidade em relação aos micro-organismos livres. / Symbiotic microparticles were produced with a lipid carrier, obtained by spray chilling technology. In this study were used two strains of probiotic (L. acidophilus-LA and L. rhamnosus-LR) and two prebiotics (inulin and polydextrose) as active or core materials. The resistance of these probiotics to the spray chilling process was evaluated, as well as the viability of the solid lipid microparticles (SLMs) during the exposition to the simulated gastric and intestinal fluids and stability during 120 days of storage at -18, 7 and 22°C, in vacuum or controlled relative humidity. Morphology characterization, particle size, water activity, thermal analysis (DSC), infrared spectroscopy and X-ray diffraction (XRPD) were studied. Spray chilling process was configured as a suitable technology to probiotics due to low loss of viable cells in processing of the particle, and no interference was observed from the presence/absence and type of prebiotic component. MSLs were obtained with relatively uniform spherical surface, and average size between 62.4 ± 2.8 µm to 69.6 ± 5.1 µm, there was no significant difference between formulations. Analyses of X-ray diffraction indicated that there were no polymorphic changes during refrigerated storage of SLMs. As for the thermal analysis it can be said that the presence of probiotics and prebiotics had practically no effect on the melting temperature for all formulations, which was 45.37° C up to 47.58° C, inferring with this the absence of significant interactions between the lipid carrier and microencapsulated ingredients, absence that was reaffirmed by the infrared spectra. Microencapsulation favored the survival against gastric and simulated intestinal fluids, and was possible to maintain viable cells up to 106 CFU per gram up to 120 days of storage for formulation with L. acidophilus and polydextrose in low temperatures and relative humidity (11%), which the stability was influenced by the water activity of the particle, which in turn is affected by the incorporation of prebiotics to the formulation of the SLMs. Given the potential of SLMs developed, they were incorporated into the ice cream. In this matrix microparticles not performed well, either on the survival of L. acidophilus during product storage, such as in protection against exposure to simulated gastrointestinal conditions. Furthermore, the addition of SLMs on strawberry ice cream was evaluated with grades significantly lower (p ≤ 0.05) in the attributes texture, flavor and overall acceptability compared to the control samples and with added of free probiotic sensory analysis of the product developed. The lipid microparticles produced were shown to be suitable as a food ingredient, but the ice cream did not meet the assumptions of protection and extension of appropriate probiotic counts. The MSLs were also incorporated in the fruit pulp, avocado and melon, in this application the SLMs provided protection to the micro-organism increasing the probiotic viability in relation to the free microorganisms.

Os cálices do hibisco possuem uma grande quantidade de compostos bioativos responsáveis pela sua atividade antioxidante. O presente trabalho teve como objetivos a obtenção de extratos contendo esses compostos bioativos em solução aquosa com 2 % de ácido cítrico por extração assistida por micro-ondas (EAM) e o encapsulamento desses extratos por atomização e liofilização utilizando polidextrose (PD), proteína isolada do soro de leite (WPI) e a mistura destes na concentração de 10 %. Previamente foram estudados três métodos de extração, o primeiro usando somente EAM a 200, 300 e 700 W de potência, e tempos de 2, 5 e 8 minutos; o segundo consistiu de dois períodos, a extração aquosa ácida com tempos de 1, 2, 4, 6, 18 e 24 horas seguida de EAM nas potências de 200, 300 e 700 W; o terceiro consistiu de EAM seguida de extração aquosa ácida, nos mesmos tempos e potências citados para o segundo método. Os resultados indicaram que a melhor condição do primeiro método foi a 700 W e 8 min, do segundo método realizada a 6 horas de extração aquosa ácida, seguida de EAM a 700 W por 8 min e do terceiro método, EAM a 700 W por 8 min seguida de 6 horas de extração aquosa ácida. Quando os três métodos foram comparados, a melhor condição de extração foi aquela obtida no terceiro método: 1,63 mg delfinidina-3-sambubiosídeo · g-1; 29,62 mg EAG · g-1; 133,25 μmol ET · g-1 para antocianinas, fenólicos totais e atividade antioxidante por ABTS, respectivamente. Para avaliar o efeito da extração obtida somente por EAM, os extratos obtidos por extração exaustiva com metanol por 25 min e EAM a 700 W e 8 min foram quantificados por HPLC-DAD-ESI-MS/MS, sendo encontrados 13 compostos (6 ácidos fenólicos, 2 antocianinas e 5 flavonóides derivados da quercetina, kaempferol e miricetina). Os compostos fenólicos majoritários foram o ácido 3-cafeoilquínico (2,58 e 1,32 mg · g-1) e ácido 5-cafeoilquínico (1,71 e 0,90 mg · g-1) para extração exaustiva e EAM, respectivamente. Esse mesmo extrato (700 W e 8 min) foi encapsulado por atomização (160 °C) e liofilização (- 68 °C por 54 horas). Os pós obtidos foram avaliados quanto aos teores de compostos fenólicos totais, antocianinas monoméricas totais, atividade antioxidante (ABTS, DPPH e HRSA), medidas por análises espectrofotométricas, atividade de água, umidade, higroscopicidade, solubilidade, eficiência de encapsulação, cor, análise termogravimétrica, temperatura de transição vítrea, espectroscopia de infravermelho com transformada de Fourier (FTIR) e microestrutura (MEV). Os pós atomizados tiveram menor atividade de água (0,14 a 0,17), umidade (3,4 a 4,5 %), higroscopicidade (23,9 a 34,1 %), solubilidade (86 a 98,2 %) e eficiência de encapsulação (51,62 a 84,52 %) do que os pós liofilizados. Os resultados do FTIR mostraram que os encapsulantes não interagiram quimicamente, visto que não foram observados mudanças na frequência dos picos; as provas termogravimétricas indicaram que os pós apresentaram a mesma tendência nas perdas de massa. Na análise de microestrutura foi observado um melhor desempenho nas micropartículas atomizadas com PD, as quais mostraram partículas mais esféricas e sem tendência de atração e aderência entre si. Foram obtidas retenções de 38 a 77 % para antocianinas monoméricas totais, 42 a 89 % para compostos fenólicos totais, e entre 33 e 90 % para atividade antioxidante nos pós obtidos. O pó encapsulado liofilizado com 10 % de polidextrose mostrou uma maior retenção de antocianinas (77 %), atividade antioxidante por DDPH (90 %) e HRSA (74 %), entretanto com maior higroscopicidade (39,4 %). As provas aceleradas de estocagem (umidades relativas de 75 e 90 % em temperaturas de 40 e 60 °C) realizadas em todos os pós encapsulados, após 30 dias, indicaram que o tratamento liofilizado com 10 % de PD foi o que apresentou melhores resultados a essas condições, retendo 75 % dos compostos fenólicos, com atividades antioxidantes medidas por ABTS, DPPH e HRSA de 75, 90 e 74 %, respectivamente, existentes no extrato original. O pó obtido tem potencial para aplicação em alimentos, portanto, devido ao hibisco ser uma matriz com ampla composição de compostos bioativos. / The hibiscus calyces contend a high quantity of bioactive compounds responsible for their antioxidant activity. The present paper was aimed the production of extracts containing those bioactive compounds in acidified aqueous solution 2 % of citric acid by microwave assisted extraction (MAE) and the encapsulation of those extracts by spray drying and freeze-drying using polydextrose (PD), whey protein isolate (WPI) and their mixture in the concentration of 10 %. Previously three methods of extraction were studied, the first using only MAE at 200, 300 and 700 W of power, and times of 2, 5 and 8 minutes; the second consisted of two steps, the acid aqueous extraction with times of 1, 2, 4, 6, 18 and 24 hours followed by MAE at the powers of 200, 300 and 700 Watts; the third consisted of MAE followed by acid aqueous extraction, in the same times and powers mentioned for the second method. The results indicated that the best condition of the first method was 700 W and 8 minutes, the second method performed at 6 hours of acid aqueous extraction, followed by MAE at 700 W for 8 minutes and the third method, MAE at 700 W for 8 minutes followed by 6 hours of acid aqueous extraction. When the three methods are compared, the best condition of extraction was obtained in the third method: 1.63 mg delphinidin-3-sambubioside · g-1; 29.62 mg GAE · g-1; 133.25 μmol TE · g-1 for total monomeric anthocyanins, total phenolic compounds and antioxidant activity by ABTS, respectively. To evaluate the effect of the extraction obtained only by MAE, the extracts obtained by exhaustive extraction with methanol for 25 minutes and MAE at 700 W and 8 minutes were quantified by HPLC-DAD-ESI-MS/MS, was found 13 compounds (6 phenolic acids, 2 anthocyanins and 5 flavonoids derived from quercetin, kaempferol and myricetin). The phenolic compounds majorities were acid 3-caffeoylquinic (2.58 e 1.32 mg · g-1) and acid 5-caffeoylquinic (1.71 e 0.90 mg · g-1) for exhaustive extraction and MAE, respectively. That same extract (700 W and 8 minutes) was encapsulated by spray drying (160 ºC) and freeze-drying (- 68 °C for 54 hours). The obtained powders were evaluated about the levels of total phenolic compounds, total monomeric anthocyanins, antioxidant activity (ABTS, DPPH e HRSA), measured by spectrophotometric analysis, water activity, moisture, hygroscopicity, solubility, encapsulation efficiency, color, thermogravimetric analysis, glass transition temperature, Fourier transform infrared spectroscopy (FTIR) and microstructure (MEV). The spray dried powders had lower water activity (0.14 to 0.17), moisture (3.4 to 4.5 %), hygroscopicity (23.9 to 34.1 %), solubility (86 to 98.2 %) and encapsulation efficiency (51.62 to 84.52 %) than the freeze-dried powders. The results of FTIR showed that the encapsulants did not interact chemically, since changes were not observed on the frequency of the peaks; the thermogravimetric tests indicated that the powders presented the same tendency on the mass loss. On the microstructure analysis a better perform was observed on the spray dried microparticles with PD, which showed more spherical particles and with no tendency of attraction and adherence between them. Were obtained retentions of 38 to 77 % for total monomeric anthocyanins, 42 to 89 % for total phenolic compounds and between 33 and 90 % for antioxidant activity in the obtained powders. The encapsulated power by freeze-drying, with 10 % of polydextrose, was showed higher retention of anthocyanins (77 %), antioxidant activity by DDPH (90 %) and HRSA (74 %), however with higher hygroscopicity (39.4 %). The accelerated tests of storage (relative humidity of 75 and 90 % in temperatures of 40 and 60 ºC) performed in all the encapsulated powders, after 30 days, indicated that the freeze-drying treatment with 10 % of PD has the best behavior in those conditions, retaining 75 % of the phenolic compounds, with antioxidant activities measured by ABTS, DPPH and HRSA of 75, 90 and 74 %, respectively, present in the original extract. The obtained powder has potential for application in foods, therefore, due to the hibiscus being a matrix with ample composition of bioactive compounds.

O consumo da uva e seus derivados está associado com a proteção contra doenças degenerativas devido a seu conteúdo de compostos fenólicos. A casca de uva é um subproduto da produção de suco de uva e vinho, que possui um alto conteúdo de compostos fenólicos, os quais se extraídos e protegidos por encapsulamento, agregariam valor a esse produto. O objetivo deste trabalho foi separar os compostos fenólicos do extrato aquoso acidificado com ácido cítrico 2% (p/v) da casca de uva a través de ultrafiltração (UF) utilizando membranas de poliestersulfona com massas molares de corte 10 e 30 kDa e posterior microencapsulação dos permeados recolhidos do processo de separação, usando como agentes encapsulantes goma arábica 15% e polidextrose 15%. Inicialmente, estudou-se o desempenho das membranas a diferentes pressões transmembrana de 1,0 a 3,5 bar e temperaturas de 25, 35 e 45°C, com o intuito de definir as melhores condições de separação. Para isso, foram usadas uvas variedade bordô (vitis labrusca) do municipio de Cotiporã, Serra Gaúcha RS. As uvas foram previamente branqueadas em banho de água a 80°C por 5 minutos e posteriormente resfriadas em banho de gelo por 3 minutos. A seguir, as cascas foram separadas manualmente da polpa e colocadas numa solução acidificada com ácido cítrico 2% (p/v) na proporção 1:4 (m/v). Após 20 horas, o extrato acidificado, com pH menor que 2,8, foi filtrado com papel Whatman n° 1 e posteriormente colocado no equipamento de membranas para realizar os diferentes experimentos de UF. Os resultados indicaram que a melhor condição de separação na UF foi à temperatura de 25°C e 3,5 bar de pressão transmembrana. Os resultados mostraram que as permeabilidades hidráulicas para as membranas novas de 10 e 30 kDa foram 10,96 e 20,52 L.m-2.h-1.bar-1, respectivamente. Durante o processo de UF do extrato, os valores de fouling a 25°C foram de 85,9 e 89,6% para as membranas de 10 e 30 kDa, enquanto que a recuperação, após limpeza química, foi de 63,1 e 80,9%, respectivamente. Do estudo das resistências total ao fluxo, constituída pelas resistências da membrana, do fouling e da polarização por concentração, a maior foi a da polarização por concentração, com porcentagens com respeito à resistência total, de 80 a 90% e de 60 a 90% para as membrana de 10 kDa e de 30 kDa, enquanto que a do fouling foi a menor de 1 a 3% e de 2 e 15% nas membranas de 10 e de 30 kDa. As concentrações de polifenois totais na membrana de 10 kDa a 25°C foram de 7,84, 2,51 e 10,89 mg ácido gálico (GA)/g amostra seca, no retido, permeado e extrato, respectivamente. Com a membrana de 30 kDa os teores foram de 7,12, 1,62 e 10,66 mg ácido gálico (GA)/g amostra seca, no retido, permeado e extrato, respectivamente. Quanto aos flavonoides os teores obtidos com a membrana de 10 kDa foram 1,78, 0,63 e 2,51, enquanto que na membrana de 30 kDa foram de 1,60, 0,40 e 2,26 mg Catequinas/g amostra seca, no retido, permeado e extrato, respectivamente. O valor de capacidade antioxidante medido como ABTS para o extrato a 25°C foi de 127,80 equivalentes Trolox (TEAC) (μmol/g amostra seca), e no permeado de 9,10 e 16,41 μmol de trolox equivalente/g amostra seca para as membranas de 10kDa e 30kDa, respectivamente, evidenciando que foram separados poucos compostos com essa propriedade. O índice de correlação entre os teores dos compostos 9 fenólicos e de flavonoides com a capacidade antioxidante foram de 0,99 e de 0,98, respectivamente. A membrana que apresenta melhores condições para a ultrafiltração de casca de uva bordô é a membrana de 10 kDa. Para o estudo de encapsulamento foram usados os permeados de UF obtidos das membranas 10 e 30 kDa a 25°C, utilizando goma arábica 15% e polidextrose 15% como materiais encapsulantes, e posterior secagem por atomização a 140ºC. As micropartículas obtidas resultaram em teores de umidade e de atividade de água menores que 3,90% e 0,18%, respectivamente. Em relação à solubilidade, todas as amostras encapsuladas foram muito solúveis, com valores na faixa de 96,8 a 99,6%. A higroscopicidade dos pós apresentou diferença significativa entre os agentes encapsulantes sendo que a polidextrose foi a mais higroscópica. Para a cor, os parâmetos a* e b* indicaram que as amostras possuem cores entre vermelho e o azul, e de acordo com o Chroma os pós obtidos com polidextrose foram mais saturados do que os pós encapsulados com goma Arábica 15%. Quanto ao parâmetro Hue, os resultados também indicaram que as amostras se encontram no quarto quadrante do circulo cromático de cores (entre vermelho e o azul). / Consumption of grape and it’s components is associated with protection against degenerative diseases due to a high content of phenolic compounds. The grape skin is a rich source of phenolic compounds as are byproducts of grape such as grape juice and compounds found in wine made from grapes resulting in a less recognized added value to these products. Current research separates the phenolic compounds of an acidic aqueous extract with citric acid 2% (w / v) of grape skin and using ultra-filtration with poly(ether sulfone) membranes. This research material had a molecular weight cut-off of 10 and 30 kDa and subsequent micro-encapsulation of collected permeate from the separation process and used Arabic gum and polydextrose 15% as encapsulating agents. Initially the performance of the membranes was compared to different trans-membrane pressure 1,0 to 3,5 bar and temperatures of 25, 35 and 45°C, in order to define the best separation conditions. Bordo grapes (vitis labrusca) that were grown in the city of Cotiporã, region of Rio grande do sul, Brazil, were used for the experiments. Grapes were previously subjected to bleaching with water bath at 80°C for 5 minutes and followed by cooling in an ice bath for 3 minutes. Then the grape skin was manually separated from the pulp and acidified water solution with citric acid 2% (w / v) was added in a ratio of 1:4 (water / pulp). Additionally it was homogenized and the mixture maintained at room temperature for 20 hours. The acidified extract with a pH lower than 2.8 was filtered with Whatman No. 1 paper and placed on the membrane equipment to begin the different UF experiments. The results showed that better separation conditions in the UF was to 25°C and a trans-membrane pressure of 3.5 bar. Results showed that the hydraulic permeabilities for the new membranes of 10 and 30 kDa were 10,96 and 20,52 L.m-1.bar-2.h-1, respectively. During the UF process of the extract, the fouling values at 25°C were 85,9 and 89.6% for the membranes 10 and 30 kDa, while recovery after chemical cleaning was 63,1 and 80,9%, respectively. It was studied total resistance (Rt) to flow constituted by the intrinsic membrane resistance (Rm), fouling resistance (Rf) and cake layer resistance (Rc). The maximum resistance was a cake layer resistance (Rc) with percentages compared with the total resistance of 80 to 90% and from 60 to 90% for membrane 10 kDa and 30 kDa. The fouling was a lowest 1 to 3% and 2 to 15% in membranes 10 and 30 kDa. The total polyphenol concentrations in the 10 kDa membrane at 25°C were 7,84, 2,51 and 10,89 mg (GA)gallic acid/g dry sample, in the retentate, permeate and extract, respectively. With the membrane of 30 kDa, contents were 7,12, 1,62 and 10,66 mg gallic acid (GA)/g dry sample, in the retentate, permeate and extract respectively. Flavonoid contents obtained with the 10 kDa membrane were 1,78, 0,63 and 2,51, and the membrane 30 kDa were 1,60, 0,40 and 2,26 Catechins mg / g sample dry, in the retentate, permeate and extract respectively. The amount of antioxidant capacity measured as ABTS to the extract at 25°C was 127,80 Trolox equivalent (TEAC) (μmol/g dry sample) and permeate of 9,10 and 16,41 Trolox equivalent (TEAC) (μmol/g dry sample) for 11 membranes of 10 and 30 kDa respectively, showing that a few compounds were separated with this property. The correlation index between levels of flavonoids and phenolic compounds with antioxidant capacity were 0,99 and 0,98, respectively. The membrane that presents the best conditions for the ultrafiltration of the grape skin extract is 10 kDa membrane. The encapsulation study used the UF permeates obtained from the membrane process of 10 and 30 kDa to 25°C, using Arabic gum and polydextrose 15% as encapsulating agent and subsequent spray drying process at 140°C. The micro-particles obtained resulted in moisture content and lower water activity to 3.90% and 0.18, respectively. With regard to solubility, all of the encapsulated samples were very soluble, with values ranging from 96.8 to 99.6%. Hygroscopicity of powders showed significant difference between agents encapsulants and the polydextrose was the most hygroscopic. For color, parameters a * and b * indicate that the samples have color between red and blue, in accordance with the Chroma. Powders obtained with polydextrose have been more saturated than powders encapsulated with Arabic gum 15%. As for Hue parameter, the results also indicated that the samples are in the fourth quadrant of the circle chromatic color (from red to blue).

<p>Savremene svetske tendencije upućuju na sve &scaron;iru primenu<br />ekstrakata lekovitog i aromatičnog bilja, kako u prehrambenim<br />proizvodima&ndash; funkcionalna hrana, tako i u proizvodima<br />farmaceutske i kozmetičke industrije. Ekstrakti biljnog<br />materijala, dobijeni primenom ugljendioksida pod pritiskom,<br />sadrže termički nepromenjene aktivne komponente, te se<br />poslednjih godina sve vi&scaron;e primenjuju u farmaceutskoj i<br />prehrambenoj industriji.<br />Cilj ove doktorske disertacije je da se ispita mogućnost<br />inkorporiranja ekstrakta nevena (<em>Calendula officinalis</em> L.), kao<br />farmakolo&scaron;ki aktivne materije, u mikrokapsule sa ciljem za&scaron;tite<br />od spolja&scaron;njih uticaja, produžetka njegovog delovanja i<br />pro&scaron;irenja mogućnosti primene.<br />Za dobijanje ekstrakata nevena primenjeni su postupci<br />ekstrakcije ugljendioksidom u tečnom i superkritičnom stanju.<br />Definisani su uslovi pri kojima je moguće dobiti ekstrakat sa<br />visokim sadržajem etarskog ulja, nosiocem gastro-intestinalnog<br />delovanja (200 bar, 40^oC). Totalni ekstrakt dobijen pod ovim<br />uslovima ekstrakcije je odabran za dobijanje mikrokapsula.<br />Ispitivana je mogućnosti primene polimer&ndash;PAM interakcije<br />nejonskih derivata celuloze- hidroksipropilmetil celuloze<br />(HPMC) i anjonske PAM- natrijum dodecilsulfata (SDS), za<br />formiranje omotača mikrokapsula. Primenom konduktometrijske<br />i viskozimetrijske metode, određene su karakteristične<br />koncentracije pri kojima HPMC&ndash;SDS interakcija započinje i<br />zavr&scaron;ava se. Definisan je uticaj osobina molekula HPMC<br />(molekulska masa, stepen supstitucije, vrsta supstituenta) i<br />temperature na &scaron;irinu intervala interakcije i obja&scaron;njeni<br />mehanizmi njihovog povezivanja, sa osvrtom na strukturu i<br />osobine formiranih HPMC/SDS komleksa. Reolo&scaron;kim<br />ispitivanjima pri različitim uslovima definisane su promene u<br />pona&scaron;anju sistema u zavisnosti od HPMC&ndash;SDS interakcije.<br />Ispitivan je uticaj interakcije na osobine 20% emulzija<br />suncokretovog ulja u vodi određivanjem njihovih reolo&scaron;kih<br />osobina, veličina i raspodela veličina kapi i praćenjem<br />stabilnosti. Utvrđeno je da se u oblasti najizraženije HPMC&ndash;SDS interakcije, odnosno kada se na granici faza ulje-voda<br />nalazi umrežen HPMC/SDS kompleks, dobijaju emulzije<br />najveće stabilnosti, sa njajmanjim srednjim prečnikom kapi.<br />Su&scaron;enjem emulzija, primenom spray drying postupka,<br />dobijene su mikrokapsule uljnog sadržaja, stabilizovane<br />kompleksom HPMC/SDS. Najbolje karakteristike mikrokapsula<br />(mehanička otpornost, morfolo&scaron;ke karakteristike, sposobnost<br />redispergovanja, veličina i raspodela veličina čestica i količina<br />inkapsuliranog ulja), dobijene u oblasti najizraženije interakcije.<br />Dodatak odabranog CO₂ ekstrakta nevena u uljnu fazu<br />emulzija ne menja značajno njihove osobine, kao ni osobine iz<br />njih dobijenih mikrokapsula.<br />Ispitivanja sprovedena u ovoj doktorskoj disertaciji<br />pokazala su da se osobine kompleksa polimer/PAM mogu<br />iskoristiti za mikrokapsulaciju ulja kao nosača farmakolo&scaron;ki<br />aktivnih materija.</p> / <p>Contemporary global trends in food- functional food,<br />pharmaceutical and cosmetic industry as well have been<br />focused on a wider medical plants extracts application during<br />the recent decade. Plant extracts obtained by means of carbon<br />dioxide under high pressure contained all unchanged active<br />compounds from plant, so that they have became more<br />popular for application in food and pharmaceuticals recently.<br />The aim of this thesis was to investigate the possibility to<br />incorporate marigold extract (<em>Calendula officinalis</em> L.), as a<br />pharmacologicaly active compound, into microcapsules in<br />order to protect them from surrounding medium, improve<br />their activity and enlarge application.<br />Marigold extracts were obtained by means of carbon<br />dioxide- CO2 under subcritical and supercritical conditions.<br />Extraction conditions under which obtained extract has high<br />content of essential oil, responsible for gastrointestinal<br />activity, were determined (200bar and 40^oC). Total extract<br />obtained under such conditions, was chosen for microcapsule<br />preparation. Application possibility of polymer&ndash;surfactant<br />interaction between non-ionic cellulose derivativehydroxypropylmethyl<br />cellulose (HPMC) and anionic<br />surfactant- sodium dodecylsulfate (SDS) to microcapsule<br />wall formation was investigated. Characteristic<br />concentrations at which interaction starts and ends were<br />determined by means of conductometric and viscometric<br />measurements. The influence of HPMC molecular<br />characteristics (molecular weight, degree of substitution and<br />substituents kind) and temperature on interaction were<br />determined and, considering the structure and characteristics<br />of HPMC/SDS complexes, binding mechanism was<br />explained. The changes in HPMC-SDS system caused by<br />their interaction were defined by rheological investigations<br />that took place under various conditions.<br />The influence of interaction on the properties of 20%<br />sunflower oil/water emulsion was investigated by rheology<br />measurement, particle size and particle size distribution<br />determination and stability testing. It was provided that<br />emulsions prepared in the region of pronounced HPMC&ndash;SDS<br />interaction, where HPMC/SDS complex is adsorbed at the</p><p>o/w interface, have highest stability and smallest particle<br />mean diameter.<br />Microcapsules were obtained by spray drying of<br />emulsions stabilized with HPMC/SDS complex. The best<br />characteristics (mechanical resistance, morphological<br />characteristics, redispersing ability, particle size and particle<br />size distribution and amount of encapsulated oil) have<br />microcapsules obtained in the region of most pronounced<br />interaction.<br />Addition of marigold CO₂ extract in to the oil phase of<br />emulsions has no significant influence neither on their, nor on<br />corresponding microcapsules characteristics<br />Investigations conducted in this thesis showed that<br />characteristics of polymer/surfactant complexes can be used<br />in microencapsulation of oil as carrier of pharmacologically<br />active compounds</p>

京都大学 / 新制・課程博士 / 博士(農学) / 甲第23520号 / 農博第2467号 / 新制||農||1086(附属図書館) / 学位論文||R3||N5351(農学部図書室) / 京都大学大学院農学研究科食品生物科学専攻 / (主査)教授 谷 史人, 教授 保川 清, 准教授 中川 究也 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Thermal energy storage (TES) consists in storing heat for a later use, thereby reducing the gap between energy availability and demand. The most diffused materials for TES are the organic solid-liquid phase change materials (PCMs), such as paraffin waxes, which accumulate and release a high amount of latent heat through a solid-liquid phase change, at a nearly constant temperature. To avoid leakage and loss of material, PCMs are either encapsulated in inert shells or shape-stabilized with porous materials or a nanofiller network. Generally, TES systems are only a supplementary component added to the main structure of a device, but this could unacceptably rise weight and volume of the device itself. In the applications where weight saving and thermal management are both important (e.g. automotive, portable electronics), it would be beneficial to embed the heat storage/management in the structural components. The aim of this thesis is to develop polymer composites that combine a polymer matrix, a PCM and a reinforcing agent, to reach a good balance of mechanical and TES properties. Since this research topic lacks a systematic investigation in the scientific literature, a wide range of polymer/PCM/reinforcement combinations were studied in this thesis, to highlight the effect of PCM introduction in a broad range of matrix/reinforcement combinations and to identify the best candidates and the key properties and parameters, in order to set guidelines for the design of these materials. The thesis in divided in eight Chapters. Chapter I and II provide the introduction and the theoretical background, while Chapter III details the experimental techniques applied on the prepared composites. The results and discussion are then described in Chapters IV-VII. Chapter IV presents the results of PCM-containing composites having a thermoplastic matrix. First, polyamide 12 (PA12) was melt-compounded with either a microencapsulated paraffin (MC) or a paraffin powder shape-stabilized with carbon nanotubes (ParCNT), and these mixtures were used as matrices to produce thermoplastic laminates with a glass fiber fabric via hot-pressing. MC was proven more suitable to be combined with PA12 than ParCNT, due to the higher thermal resistance. However, also the MC were considerably damaged by melt compounding and the two hot-pressing steps, which caused paraffin leakage and degradation, as demonstrated by the relative enthalpy lower than 100 %. Additionally, the PCM introduction decreased the mechanical properties of PA12 and the tensile strength of the laminates, but for the laminates containing MC the elastic modulus and the strain at break were not negatively affected by the PCM. Higher TES properties were achieved with the production of a semi-structural composite that combined PA12, MC and discontinuous carbon fibers. For example, the composite with 50 wt% of MC and 20 wt% of milled carbon fibers exhibited a total melting enthalpy of 60.4 J/g and an increase in elastic modulus of 42 % compared to the neat PA. However, the high melt viscosity and shear stresses developed during processing were still responsible for a not negligible PCM degradation, as also evidenced by dynamic rheological tests. Further increases in the mechanical and TES properties were achieved by using a reactive thermoplastic matrix, which could be processed as a thermosetting polymer and required considerably milder processing conditions that did not cause PCM degradation. MC was combined with an acrylic thermoplastic resin and the mixtures were used as matrices to produce laminates with a bidirectional carbon fabric, and for these laminates the melting enthalpy increased with the PCM weight fraction and reached 66.8 J/g. On the other hand, the increased PCM fraction caused a rise in the matrix viscosity and so a decrease in the fiber volume fraction in the final composite, thereby reducing the elastic modulus and flexural strength. Dynamic-mechanical investigation evidenced the PCM melting as a decreasing step in ’; its amplitude showed a linear trend with the melting enthalpy, and it was almost completely recovered during cooling, as evidenced by cyclic DMA tests. Chapter V presents the results of PCM-containing thermosetting composites. A further comparison between MC and ParCNT was performed in a thermosetting epoxy matrix. First, ParCNT was mixed with epoxy and the mixtures were used as matrices to produce laminates with a bidirectional carbon fiber fabric. ParCNT kept its thermal properties also in the laminates, and the melting enthalpy was 80-90 % of the expected enthalpy. Therefore, ParCNT performed better in thermosetting than in thermoplastic matrices due to the milder processing conditions, but the surrounding matrix still partially hindered the melting-crystallization process. Therefore, epoxy was combined with MC, but the not optimal adhesion between the matrix and the MC shell caused a considerable decrease in mechanical strength, as also demonstrated by the fitting with the Nicolais-Narkis and Pukanszky models, both of which evidenced scarce adhesion and considerable interphase weakness. However, the Halpin-Tsai and Lewis-Nielsen models of the elastic modulus evidenced that at low deformations the interfacial interaction is good, and this also agrees with the data of thermal conductivity, which resulted in excellent agreement with the Pal model calculated considering no gaps at the interface. These epoxy/MC mixtures were then reinforced with either continuous or discontinuous carbon fibers, and their characterization confirmed that the processing conditions of an epoxy composite are mild enough to preserve the integrity of the microcapsules and their TES capability. For continuous fiber composites, the increase in the MC fraction impaired the mechanical properties mostly because of the decrease in the final fiber volume fraction and because the MC phase tends to concentrate in the interlaminar region, thereby lowering the interlaminar shear strength. On the other hand, a small amount of MC enhanced the mode I interlaminar fracture toughness (Gic increases of up to 48 % compared to the neat epoxy/carbon laminate), as the MC introduced other energy dissipation mechanisms such as the debonding, crack deflection, crack pinning and micro-cracking, which added up to the fiber bridging. Chapter VI introduces a fully biodegradable TES composite with a thermoplastic starch matrix, reinforced with thin wood laminae and containing poly(ethylene glycol) as the PCM. The wood laminae successfully acted as a multifunctional reinforcement as they also stabilized PEG in their inner pores (up to 11 wt% of the whole laminate) and prevent its leakage. Moreover PEG was proven to increase the stiffness and strength of the laminate, thereby making the mechanical and TES properties synergistic and not parasitic. Finally, Chapter VII focused on PCM microcapsules. The synthesis of micro- and nano-capsules with an organosilica shell via a sol-gel approach clarified that the confinement in small domains and the interaction with the shell wall modified the crystallization behavior of the encapsulated PCM, as also evidenced by NMR and XRD studies and confirmed by DSC results. In the second part of Chapter VII, a coating of polydpamine (PDA) deposited onto the commercial microcapsules MC. The resulting PDA coating was proven effective to enhance the interfacial adhesion with an epoxy matrix, as evidenced by SEM micrographs. XPS demonstrated that the PDA layer was able to react with oxirane groups, thereby evidencing the possibility of forming covalent bond with the epoxy matrix during the curing step.

Active substances can be stabilized to be protected from undesirable reactions, aggregation, and leaking, which would keep the intended functions of the active substances without premature degradation. Among such active substances are paraffin-based organic phase change materials (PCMs) and essential oils (EOs), which feature attractive characteristics, e.g., high latent heat of fusion and inherent antimicrobial activity. However, their high volatility requires an effective stabilization strategy. Petroleum-based synthetic polymers have often been employed to stabilize PCMs and EOs by encapsulation and complexation pathways. Despite their proven effectiveness, these polymers are from non-renewable resources, and non-degradable and often toxic, which has prompted a need to develop a substitute arising from natural polymers that are environmentally benign, biodegradable, and sustainable. Valorization of biomass in this regard would add extra value to biomass otherwise burned or wasted. This dissertation will present the development of microcapsules and inclusion complexes consisting of a hydrophobic active substance core and a polysaccharidic shell originating from biomass. The first two chapters will explain the introduction and experimental details. Chapter 3 will present the microencapsulation of n-hexadecane as PCM via oil-in-water (O/W) Pickering emulsions stabilized by unmodified cellulose nanofibrils (CNFs) through a sonochemical technique. Chapter 4 will investigate the incorporation of the PCM-CNF microcapsules into TEMPO-oxidized CNF films for building application. Finally, Chapter 5 will show the synthesis of EOs-beta cyclodextrin (βCD) inclusion complexes as a guest-host system through a sonochemical technique.