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Consultar: Programa de Ps-Graduao em Cincia de Alimentos

Incio > Dissertaes e Teses > Cincias Agrrias > Cincia e Tecnologia de Alimentos > Programa de Ps-Graduao em Cincia de Alimentos

Ttulo [PT]: Microencapsulao de Norbixinato de potssio e Curcumina com Maltodextrina : avaliao da estabilidade e aplicao em alimentos
Autor(es): Mirian Sousdaleff
Palavras-chave [PT]:

Maltodextrinas. Curcumina. Norbixinato de potssio. Microencapsulao. Corantes naturais. Alimentos. Aditivos. Brasil.
Titulao: Mestre em Cincia de Alimentos
Banca:
Gracciette Matioli [Orientador]
Resumo:
Resumos: A cor um atributo decisivo na escolha de um alimento que est correlacionada diretamente qualidade do produto. Tambm, vem crescendo, por parte dos consumidores, a exigncia por produtos de origem natural, o que faz com que a indstria do setor alimentcio busque substituio gradativa de corantes sintticos, que exibem relatos de toxicidade, por corantes naturais. O urucum o corante natural com maior obteno de seus extratos e aplicao pela indstria brasileira e, tambm, representa mundialmente significante utilizao. Os extratos hidrossolveis do urucum, representados pelo norbixinato (sais da norbixina) ampliam o seu emprego. A curcumina originria da ndia tem merecida ateno, tanto na aplicao como corante quanto um potencial agente teraputico. Conforme exposto, o presente trabalho teve por objetivo a formao de microcpsulas de norbixinato de potssio e curcumina com maltodextrina DE20, utilizando secagem por liofilizao com o intuito de melhorar a estabilidade destes dois corantes e realizar a aplicao em alimentos. As formulaes para obteno das microcpsulas contendo os corantes foram conduzidas por meio do preparo de solues aquosas para o norbixinato de potssio e soluo etanlica para a curcumina. Em cada uma das solues contendo os corantes foi adicionada soluo aquosa do agente microencapsulante maltodextrina DE20. As respectivas solues foram agitadas por um perodo de 30min a 2500rpm, sendo posteriormente congeladas com nitrognio lquido e submetidas a secagem por liofilizao. As solues foram preparadas resultando nas propores de 1:10 e 1:20 para norbixinato de potssio maltodextrina e na proporo de 1:20 de curcumina com maltodextrina. Foram realizados testes de estabilidade dos corantes e das microcpsulas obtidas com a finalidade de se avaliar o grau de proteo exercido pela maltodextrina DE20. As primeiras anlises aplicadas foram com relao a estabilidade dos corantes e das formulaes armazenados sob condies de presena e ausncia de luz natural, e quanto a presena de ar atmosfrico, na qual as formulaes foram embaladas vcuo e em embalagens de polietileno na presena de oxignio. Avaliou-se a porcentagem de reteno dos corantes quando submetidos aos testes de estabilidade com obteno de amostras das embalagens analisadas espectrofotometricamente, por um perodo de 30 dias. Os corantes e as respectivas propores obtidas mediante o processo de microencapsulamento foram submetidos avaliao da estabilidade frente ao pH na faixa de 1 a 9. Avaliou-se tambm, com relao solubilidade em gua, medindo-se o tempo de solubilizao, o comportamento dos corantes e das microcpsulas em solues preparadas a 0,3%, A microscopia eletrnica de varredura foi empregada para a visualizao dos detalhes estruturais dos corantes e das microcpsulas obtidas pelo processo de secagem por liofilizao. As medidas referentes s anlises trmicas aplicadas neste estudo, Calorimetria diferencial de varredura (DSC) e Termogravimetria (TG), foram realizadas simultaneamente, avaliando o comportamento trmico dos corantes naturais norbixinato de potssio e curcumina e das respectivas propores de microcpsulas obtidas, que foram alocados em cpsulas de platina com avaliao a partir da temperatura ambiente at 500C, com taxa de aquecimento de 10C/min, em atmosfera de oxignio (20 mL/min). A tcnica de Espectroscopia Fotoacstica (PAS) foi empregada com o objetivo de avaliar a proteo exercida pelo filme formado da maltodextrina sobre os corantes norbixinato de potssio e curcumina, como tambm dos corantes no microencapsulados, primeiramente sendo alocados em um porta-amostras para obteno dos espectros de absoro ptica e em uma segunda etapa, aps exposio dos mesmos por 2h em luz branca (lmpada de Xennio), com potncia de 80mW. 11 A aplicao dos corantes em alimentos foi realizada com o preparo de macarro (tipo espaguette) em extrusora, utilizando-se de duas formulaes, uma para o corante norbixinato de potssio livre e a outra para o corante microencapsulado na proporo de 1:10. Cada amostra foi preparada adicionando-se na formulao 0,25% de corante. A curcumina e a curcumina microencapsulada foram aplicadas na elaborao de sorvete de creme na porcentagem de 0,5% para cada uma das duas formulaes preparadas. As anlises sensoriais foram conduzidas por meio da aplicao de Teste Afetivo utilizando-se de Escala Hednica, com painel de provadores no treinados, por meio de fichas de avaliao, nas quais constava uma escala de 1 a 9 (desgostei muitssimo a gostei muitssimo) e inteno de compra. As anlises por colorimetria foram aplicadas nos produtos preparados com o objetivo de se avaliar a cor a cada 5 dias por um perodo de 15 dias. Os resultados indicaram que a estabilidade das formulaes avaliadas frente luz natural e no escuro, na presena e ausncia de ar atmosfrico, apresentaram uma diferena de 10% com relao ao norbixinato de potssio livre e o mesmo corante microencapsulado nas propores de 1:10 e 1:20 das amostras que permaneceram no escuro em relao as que foram expostas luz ao final de 30 dias. Em presena de luz, a melhor reteno foi para o norbixinato de potssio microencapsulado na proporo 1:20 e embalado vcuo, com uma reteno de 78%. J para curcumina no claro, a melhor estabilidade foi observada para a amostra microencapsulada embalada vcuo com 71% de reteno de cor. Estudos anteriores verificaram que altamente recomendado para urucum a excluso de ar atmosfrico a fim de minimizar reaes indesejadas. Com isto os melhores resultados foram monitorados por meio de leituras dos espectros de absoro sendo que a diferena de concentrao do norbixinato de potssio microencapsulado entre 0 e 30 dias foi de 1,1 ?g/mL e para a curcumina, de apenas 0,7 ?g/mL. A solubilidade total em gua para o corante norbixinato de potssio livre foi observada num perodo de 20s, j para o norbixinato de potssio microencapsulado nas propores de 1:10 e 1:20 foram necessrios 25s e 30s, respectivamente. No caso da curcumina livre, a solubilidade utilizando-se gua como solvente no foi resolvida, e para a curcumina microencapsulada em maltodextrina com um tempo de solubilizao de 1 minuto e 35 segundos, sem apresentar aglomeraes e precipitaes, mostrando que o processo de microencapsulamento combinado com liofilizao forneceu uma melhora para a solubilizao deste corante. As duas propores de microcpsulas obtidas aps a tcnica de liofilizao do norbixinato de potssio com maltodextrina apresentaram comportamento muito semelhante quando submetidos as diferentes faixas de pH, apresentando uma certa estabilidade na faixa entre 7 a 9. Para a curcumina microencapsulada foi praticamente invarivel o comportamento nas faixas de pH entre 1 a 8, porm a curcumina livre sofreu alteraes expressivas na faixa entre 6 a 9. A curcumina livre precipitada em condies de acidez e a sua cor alterada para uma tonalidade vermelho-tijolo em condies de alcalinidade, o que restringe sua aplicao em alimentos, fato este que no foi observado neste estudo quando este corante foi microencapsulado com maltodextrina, sugerindo uma proteo deste agente encapsulante ao corante. As imagens apresentadas pela tcnica de microscopia de varredura apresentaram para a curcumina microencapsulada por meio de processo de liofilizao, uma superfcie relativamente lisa, morfolologia bastante semelhante em relao a outros estudos realizados com esta tcnica, enquanto que para as microcpsulas de norbixinato de potssio, as superfcies observadas apresentaram-se mais rugosas com aglomerados e poucos poros.

Summary general: Color is a critical attribute in choosing a food that is directly correlated to product quality. Also, growing on the part of consumers, the demand for natural products, which makes the food industry sector to seek gradual replacement of synthetic dyes, that reported toxicity by natural dyes. The annatto is the more natural dye extracts and getting your application for the Brazilian industry and also represents a significant world wide use. The water-soluble annatto extracts, represented by norbixinate (salts of norbixin) extend their employment. Curcumin from India has deserved attention, both in the application as a dye as a potential therapeutic agent. As stated, this study aimed at the formation of microcapsules potassium norbixinate with maltodextrin DE20 and curcumin with maltodextrin, drying using lyophilization in order to improve the stability of these two colors and make the food application. The formulations to obtain the microcapsules containing the dyes were conducted through the preparation of aqueous solutions for potassium norbixinate and ethanolic solution for curcumin. In each of the solutions containing the dye was added aqueous solution of Maltodextrin DE20 microencapsulant agent. The respective solutions were agitated for a period of 30 minutes at 2500rpm, and was then frozen with liquid nitrogen and dried by lyophilization. The resulting solutions were prepared in ratios of 1:10 and 1:20 for potassium norbixinate (annatto) and maltodextrin at a ratio of 1:20 of curcumin with maltodextrin. Tests were carried out colors and stability of the microcapsules obtained in order to assess the degree of protection exerted by maltodextrin DE20. The first tests were applied with respect to stability of dyes and formulations stored under conditions of presence and absence of natural light, and the presence of air, in which the formulations were vacuum packed in polyethylene and in the presence of oxygen. We evaluated the percentage of dye retention when tested for stability with getting samples analyzed spectrophotometrically packaging, for a period of 30 days. The colors and proportions obtained by the process of microencapsulation were evaluated for their stability against the pH range 1-9. We also evaluated with respect to solubility in water, measuring the time of dissolution, the colors and behavior of the microcapsules prepared in solutions of 0.3%, scanning electron microscopy was used to visualize structural details of dyes and the microcapsules obtained by the process of drying by lyophilization. The measures in this study applied thermal analysis, differential scanning calorimetry (DSC) and thermogravimetry (TG) were performed simultaneously evaluating the thermal performance of natural dyes potassium norbixinate and curcumin and their ratios obtained microcapsules, which were allocated platinum capsules with evaluation from room temperature to 500C with a heating rate of 10C / min in oxygen atmosphere (20mL/min). The technique of photoacoustic spectroscopy (PAS) was employed to evaluate the protection exerted by the film formed on colors maltodextrin norbixinato potassium and curcumin, but not of microencapsulated dyes, first being placed in a sample holder to obtain the optical absorption spectra and in a second step, after their exposure for 2 h in white light (xenon lamp), with power of 80mW. The application of dyes in food preparation was done with the pasta (spaghetti) in the extruder, using two formulations, one for the dye potassium norbixinate free and the other for the dye in the microencapsulated ratio of 1:10. Each sample was prepared by adding 0.25% in the formulation of dye. The microencapsulated curcumin and curcumin were applied in the preparation of ice cream in the percentage of 0.5% for each of the two formulations prepared. The sensory analysis was conducted by applying affective tests using hedonic scale, with a panel of untrained tasters through evaluation forms, which contain a scale of 1 to 9 (dislike extremely to like extremely) and purchase 14 intent. The analysis by colorimetry were applied in the products prepared with the objective of evaluating the color every 5 days for a period of 15 days. The results indicated that the stability of the formulations evaluated against the natural light and dark in the presence and absence of air, showed a 10% difference with respect to potassium norbixinate free and microencapsulated dye in the same proportions of 1:10 and a 1: 20 of the samples remained in the dark about those who were exposed to light at the end of 30 days. In the presence of light, the retention was better for potassium norbixinate microencapsulated in the ratio 1:20 and vacuum-packed, with a retention of 78%. As for curcumin in the course, the best stability was observed for the sample microencapsulated vacuum packed with 71% color retention. Previous studies found that annatto is highly recommended for the exclusion of atmospheric air in order to minimize unwanted reactions. With this the best results were monitored by reading the absorption spectra and the difference of concentration of microencapsulated potassium norbixinato between 0 and 30 days was 1.1mg/mL, and curcumin, only 0.7mg/mL. The complete solubility in water for the dye potassium norbixinate free was observed over a period of 20s, as for potassium norbixinate microencapsulated in the proportions of 1:10 and 1:20 it took 25s and 30s, respectively. In the case of free curcumin, the solubility using water as solvent has not been resolved, and curcumin in microencapsulated maltodextrin with a time of solubilization of 1 minute and 35 seconds, with no agglomeration and precipitation, showing that the microencapsulation process combined lyophilization to provide an improvement for the solubilization of the dye. The two amounts of microcapsules obtained after the lyophilization technique potassium norbixinate with maltodextrin DE20, showed very similar behavior when subjected to different ranges of pH, showing a certain stability in the range between 7 and 9. For microencapsulated curcumin was practically unchanged behavior in the pH range 1-8, but the free curcumin has significant changes in the range of 6-9. Curcumin free is precipitated in acidic conditions and its color is changed to a brick-red hue in alkaline conditions, which restricts its application in food, a fact which was not observed in this study when the dye was microencapsulated with maltodextrin, suggesting protection of an encapsulating agent to the dye. The images in the technique of scanning electron microscopy showed up for the microencapsulated curcumin through lyophilization, a relatively smooth surface, morpholology quite similar in relation to other studies with this technique, while for the microcapsules norbixinato potassium, the observed surfaces were more rough with clusters and few pores. The result obtained through this visualization technique for microencapsulated curcumin showed a better interaction between the dye which is soluble and maltodextrin, used as an agent or microencapsulant wall material. In the thermal analysis of DSC, it was found that there was an off set of 4C endothermic peak representing the loss of water from potassium norbixinate for microcapsules, representing a possible interaction between dye and encapsulating agent. Maltodextrin showed also a second endothermic peak at 229C, suggesting a merger at this temperature, and the analysis of TG curves confirmed these data, if the incidence of mass loss for the respective proportions of microcapsules at 200C. With respect to curcumin, the endothermic peak of fusion molecule observed at 176C in dye free was not seen when microencapsulated, and the results for the early loss of mass for curcumin free place at a temperature of 201C, since for Microencapsulated was of 228C, indicating an alleged protection the dye. Signs Photoacustic (PAS) obtained in this study indicate a certain instability of free and microencapsulated dye after exposure to light after 2 hours in Xenon lamp, observed by the increase of the photoacoustic signal samples in the region between 300 and 500 nm. An important observation was obtained in the UV region for the encapsulating agent maltodextrin, in that it did not show the peak obtained when it was subjected to the lyophilization process, suggesting that this 15 change requires research in greater depth about the changes occurred in maltodextrin molecule to determine the stability of compounds microencapsulated by this agent. The results of sensorial analysis of the products obtained were evaluated statistically (p ≥ 0.05), especially with respect to the attribute color, have been well accepted for the microencapsulated dye. The results of colorimetric tests for microencapsulated curcumin not applied in a cream tone indicated more pronounced for the green after the expiry of 15 days, while for the microencapsulated curcumin were not significant differences in color. As for the free samples norbixinato noodle significant differences with respect to the parameters of lightness (L *), while for the same dye microencapsulated no significant difference, with a darker trend. The dyes and potassium norbixinate microencapsulated with maltodextrin DE20 curcumin, using lyophilization and drying process, most of the results presented were adequate for use by food industries. Lyophilization was presented as a positive process of microencapsulation and maltodextrin, protective agent obtained by the hydrolysis of raw materials at a lower cost of production, can be applied to achieve a better stabilization of natural dyes for use in the food industry.
Data da defesa: 2011
Cdigo: vtls000199148
Informaes adicionais:
Idioma: Portugus
Data de Publicao: 2011
Local de Publicao: Maring, PR
Orientador: Prof. Dr. Gracciette Matioli
Instituio: Universidade Estadual de Maring. Centro de Cincias Agrrias
Nvel: Dissertao (mestrado em Cincia de Alimentos)/
UEM: Programa de Ps-Graduao em Cincia de Alimentos

Responsavel: inez
Categoria: Aplicao
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