Microencapsulação por coacervação complexa de óleo de buriti: explorando materiais, processos e aplicação
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Data
2022-02-24
Autores
Lemos, Yuri Pessoa [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A microencapsulação do óleo de buriti pode proteger os compostos bioativos presentes, principalmente os carotenoides, e a coacervação complexa é uma técnica de microencapsulação efetiva para proteger compostos lipofílicos. O objetivo deste trabalho foi avançar no estudo da microencapsulação de óleo de buriti pelo processo de coacervação complexa, utilizando gelatina/alginato de sódio e gelatina/goma arábica como materiais de parede, com enfoque sobre o efeito de parâmetros de processo nas características das microcápsulas, e a sua aplicação em produtos alimentícios. Para a produção das microcápsulas foi construído um vaso de agitação obedecendo às relações geométricas recomendadas e foram testados os efeitos da frequência de agitação, do tipo de impulsor e da presença de defletores sobre a coacervação. As microcápsulas sofreram influência direta dos parâmetros de processo e os resultados puderam ser correlacionados em função dos números adimensionais Reynolds e Froude. Os tamanhos médios das partículas ficaram na faixa de 36 a 186 µm e tiveram relação inversa com o número de Reynolds. A presença dos defletores se mostrou eficaz, produzindo microcápsulas com menores dispersões de tamanho. As amostras apresentaram altos valores de eficiência de encapsulação, acima de 80%, e coloração amarelo intenso. A partir desses resultados, procurou-se investigar o efeito do comportamento reológico das soluções precursoras das microcápsulas na produção das mesmas, o que foi avaliado utilizando os pares gelatina/goma arábica e gelatina/alginato de sódio. Foi possível observar que, para a formação das microcápsulas, soluções dilatantes necessitam de baixas velocidades de agitação, enquanto soluções pseudoplásticas demandam maiores velocidades de agitação. Com o intuito de explorar a possibilidade de substituir a liofilização, convencionalmente usada na secagem de microcápsulas produzidas por coacervação complexa, e assim reduzir os custos de produção, duas alternativas de secagem foram avaliadas: a secagem em leito de espuma e por formação de filme delgado. Ambas apresentaram bons resultados de eficiência de encapsulação quando comparadas às microcápsulas secas por liofilização. Por fim, a incorporação das microcápsulas em snacks extrusados de milho foi testada, visando o enriquecimento dos mesmos com carotenoides. Foram avaliadas duas estratégias de adição das microcápsulas, antes e depois da extrusão, bem como diferentes condições de processo. Os resultados foram promissores e, nas condições médias e brandas de extrusão, foi possível observar a presença de microcápsulas íntegras nos snacks produzidos, bem como foi possível detectar a presença de carotenoides no produto, em concentrações na faixa de 0,5 a 5 µg/g de snack.
Buriti oil microencapsulation can protect the bioactive compounds present, mainly carotenoids, and complex coacervation is an effective microencapsulation technique to protect lipophilic compounds. The general objective of this work was to advance in the study of microencapsulation of buriti oil by the complex coacervation process, using gelatin/sodium alginate and gelatin/gum Arabic as wall materials, focusing on the effect of process parameters on the characteristics of the microcapsules, and its application in food products. For the production of microcapsules, an agitation vessel was built following the recommended geometric relationships and the effects of agitation frequency, type of impeller and the presence of deflectors on coacervation were tested. The microcapsules were directly influenced by the process parameters and the results could be correlated as a function of the Reynolds and Froude dimensionless numbers. The average particle sizes were in the range of 186 to 36 µm and had an inverse relationship with the Reynolds number. The presence of deflectors proved to be effective, producing microcapsules with smaller size dispersions. The samples showed high values of encapsulation efficiency, above 80%, and intense yellow color. From these results, we sought to investigate the effect of the rheological behavior of the precursor solutions of the microcapsules, which was evaluated using the pairs gelatin/gum Arabic and gelatin/sodium alginate. It was possible to observe that, for the formation of microcapsules, dilatant solutions need low stirring speeds, while pseudoplastic solutions demand higher stirring speeds. In order to explore the possibility of replacing lyophilization, conventionally used in the drying of microcapsules produced by complex coacervation, and thus reducing production costs, two drying alternatives were evaluated: foam-mat drying and thin-film formation. Both showed good encapsulation efficiency results when compared to freeze-dried microcapsules. Finally, the incorporation of microcapsules in extruded corn snacks was tested, aiming to enrich them with carotenoids. Two microcapsule addition strategies were evaluated, before and after extrusion, as well as different process conditions. The results were promising and, under medium and mild extrusion conditions, it was possible to observe the presence of intact microcapsules in the snacks produced, as well as detecting the presence of carotenoids in the product, in concentrations ranging from 0.5 to 5 µg/g of snack.
Buriti oil microencapsulation can protect the bioactive compounds present, mainly carotenoids, and complex coacervation is an effective microencapsulation technique to protect lipophilic compounds. The general objective of this work was to advance in the study of microencapsulation of buriti oil by the complex coacervation process, using gelatin/sodium alginate and gelatin/gum Arabic as wall materials, focusing on the effect of process parameters on the characteristics of the microcapsules, and its application in food products. For the production of microcapsules, an agitation vessel was built following the recommended geometric relationships and the effects of agitation frequency, type of impeller and the presence of deflectors on coacervation were tested. The microcapsules were directly influenced by the process parameters and the results could be correlated as a function of the Reynolds and Froude dimensionless numbers. The average particle sizes were in the range of 186 to 36 µm and had an inverse relationship with the Reynolds number. The presence of deflectors proved to be effective, producing microcapsules with smaller size dispersions. The samples showed high values of encapsulation efficiency, above 80%, and intense yellow color. From these results, we sought to investigate the effect of the rheological behavior of the precursor solutions of the microcapsules, which was evaluated using the pairs gelatin/gum Arabic and gelatin/sodium alginate. It was possible to observe that, for the formation of microcapsules, dilatant solutions need low stirring speeds, while pseudoplastic solutions demand higher stirring speeds. In order to explore the possibility of replacing lyophilization, conventionally used in the drying of microcapsules produced by complex coacervation, and thus reducing production costs, two drying alternatives were evaluated: foam-mat drying and thin-film formation. Both showed good encapsulation efficiency results when compared to freeze-dried microcapsules. Finally, the incorporation of microcapsules in extruded corn snacks was tested, aiming to enrich them with carotenoids. Two microcapsule addition strategies were evaluated, before and after extrusion, as well as different process conditions. The results were promising and, under medium and mild extrusion conditions, it was possible to observe the presence of intact microcapsules in the snacks produced, as well as detecting the presence of carotenoids in the product, in concentrations ranging from 0.5 to 5 µg/g of snack.
Descrição
Palavras-chave
Microencapsulação, Coacervação complexa, Frequência de agitação, Óeo de buriti, Extrusados, Microencapsulation, Complex coacervation, Agitation frequency, Buriti oil, Extrudates