A carregar...
Publicação
Pectinase e Naringinase imobilizadas em quitosano e alginato: Aplicação no controlo de qualidade de sumos
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 1.95 MB | Adobe PDF |
Autores
Orientador(es)
Resumo(s)
As pectinases são enzimas que degradam substâncias pécticas, e apresentam um papel de destaque na indústria dos sumos de fruta, na melhoria da qualidade do processo e do produto.
O sabor amargo, presente em alguns sumos de fruta, é uma caraterística indesejável, principalmente atribuída à naringina. A naringinase, é um complexo enzimático que expressa atividade em α-L-ramnosidase e β-D-glucosidase, e que converte a naringina na aglicona naringenina. A naringina e a naringenina, são compostos que demonstram atividade farmacológica e biológica, como ação anti-oxidante, anti-inflamatória e anti-cancerígena, revelando um grande potencial nas indústrias alimentar e farmacêutica. O objetivo deste trabalho prendeu-se, ao desenvolvimento de esferas com pectinase e naringinase imobilizadas, com a finalidade de melhorar as características e a qualidade dos sumos e à investigação da sua aplicabilidade na produção de sumos funcionais.
Neste estudo foram utilizadas as pectinases de Aspergillus aculeatus e naringinase do Penicillium decumbens. A análise quantitativa da atividade enzimática foi efetuada pelo método colorimétrico do ácido 2,4-dinitrosalicílico (DNS). A concentração de proteína foi determinada através do método de Bradford. As enzimas foram imobilizadas pelo método de inclusão, utilizando como suportes o quitosano e o alginato de cálcio.
Os ensaios de bioconversão foram realizados com as enzimas solúveis e nas matrizes de imobilização em estudo, com avaliação de vários parâmetros como, a concentração de enzima e substrato e a estabilidade operacional. Neste trabalho foi ainda avaliado o efeito da alta pressão nos sumos (laranja, limão, toranja, framboesa e amora) com a pectinase e naringinase imobilizadas. A atividade mais elevada foi alcançada com a pectinase encapsulada em quitosano co-reticulado com tripolifosfato de sódio (TPP).
Foi ainda realizada a comparação de atividade de sumo processado e sumo não processado em modelos in vivo.
A pectinase e a naringinase apresentaram alta atividade, demostrando-se eficazes na clarificação do sumo e na redução do sabor amargo.
Pectinases are enzymes that degrade pectic substances, has potential application in fruit juices to improve the quality of the process and the product. Bitterness, one problem in some fruit juices, is mainly accomplished by naringin. Naringinase, an enzyme complex expressing α-L-rhamnosidase and β-D-glucosidase activities, degrade naringin to its aglycone, naringenin, an healthy compound with biological and pharmacological activities, such as anti-oxidant, anti-inflammatory and anti-cancer, showing a high potential in the food and pharmaceutical industries. The main goal of this work was to develop microencapsulated pectinase and naringinase in hydrogels in order to improve the characteristics and quality of juices and investigate their application in functional juices production. Pectinases from Aspergillus aculeatus and naringinase from Penicillium decumbens were tested. The quantitative analysis of enzyme activity was carried out by the 2,4-dinitrosalicylic acid (DNS) colorimetric method. The protein concentration was determined by the Bradfors´s method. Enzymes were immobilized by the inclusion method, using the chitosan and alginate as supports. The bioconversion assays were performed with soluble and immobilized enymes in the studied matrices. To improve the bioprocess, pectinase and naringinase were tested immobilized in hydrogels approved by FDA, like chitosan and calcium alginate. Several parameters were evaluated (substrates concentrations, enzymes concentrations and operational stability). The pressure effect in orange, lemon, grapefruit, raspberry and mulberry juices wih immobilized pectinase and naringinase, was also investigated. Higher activity was attained with pectinase encapsulated in chitosan beads crosslinked with TPP. Was compared the biologic activity of (un)processed fruit juices in vivo models. Pectinase and naringinase showed to be effective in clarifying juice and reducing bitterness presenting high activity.
Pectinases are enzymes that degrade pectic substances, has potential application in fruit juices to improve the quality of the process and the product. Bitterness, one problem in some fruit juices, is mainly accomplished by naringin. Naringinase, an enzyme complex expressing α-L-rhamnosidase and β-D-glucosidase activities, degrade naringin to its aglycone, naringenin, an healthy compound with biological and pharmacological activities, such as anti-oxidant, anti-inflammatory and anti-cancer, showing a high potential in the food and pharmaceutical industries. The main goal of this work was to develop microencapsulated pectinase and naringinase in hydrogels in order to improve the characteristics and quality of juices and investigate their application in functional juices production. Pectinases from Aspergillus aculeatus and naringinase from Penicillium decumbens were tested. The quantitative analysis of enzyme activity was carried out by the 2,4-dinitrosalicylic acid (DNS) colorimetric method. The protein concentration was determined by the Bradfors´s method. Enzymes were immobilized by the inclusion method, using the chitosan and alginate as supports. The bioconversion assays were performed with soluble and immobilized enymes in the studied matrices. To improve the bioprocess, pectinase and naringinase were tested immobilized in hydrogels approved by FDA, like chitosan and calcium alginate. Several parameters were evaluated (substrates concentrations, enzymes concentrations and operational stability). The pressure effect in orange, lemon, grapefruit, raspberry and mulberry juices wih immobilized pectinase and naringinase, was also investigated. Higher activity was attained with pectinase encapsulated in chitosan beads crosslinked with TPP. Was compared the biologic activity of (un)processed fruit juices in vivo models. Pectinase and naringinase showed to be effective in clarifying juice and reducing bitterness presenting high activity.
Descrição
Tese de mestrado, Controlo da Qualidade e Toxicologia dos Alimentos, Universidade de Lisboa, Faculdade de Farmácia, 2016
Palavras-chave
Pectinase Naringinase Sumos de fruta Imobilização Alta pressão Teses de mestrado - 2016