Efeito do tratamento enzimático sobre a viscosidade e os teores de fibra e pectina em suco de pitanga (Eugenia uniflora L.)

Abstract

Recebido: Set. 10, 2014 Aprovado: Out. 29, 2015 Resumo O objetivo deste trabalho foi avaliar o efeito do tratamento enzimático, utilizando enzimas comerciais, sobre o comportamento reológico e o teor de fibras e pectina do suco de pitanga. Foram avaliadas diferentes combinações de pectinase (Pectinex Ultra SP-L) e celulase (Cellubrix-L), totalizando 0,1%, em massa, de enzima. Os resultados encontrados indicaram baixo valor de pectina (<0,003%) e significativa redução no teor de fibras após tratamento enzimático, sendo que a aplicação combinada de 0,025% de pectinase com 0,075% de celulase provocou a maior redução no teor de fibras e, consequentemente, menor viscosidade do suco. Ao mesmo tempo, uma aplicação igual ou superior a 0,05% de Pectinex Ultra SP-L foi necessária para resultar nas menores concentrações de pectina. A aplicação combinada de celulase e pectinase resultou em suco com menor viscosidade, cujo comportamento reológico foi próximo ao Newtoniano. No entanto, o modelo Lei da Potência seria o mais indicado para uso em modelagens matemáticas. Palavras-chave: Pectinase; Celulase; Comportamento reológico; Suco de frutas. SummaryThe aim of this work was to evaluate the effect of the enzymatic treatment on the viscosity values and fiber and pectin contents of pitanga juice, applying commercial enzymes. Different combinations of pectinase (Pectinex Ultra SP-L) and cellulase (Cellubrix-L), giving a total mass of enzyme of 0.1%, were evaluated. The results indicated a low value for pectin (<0.003%) and a significant reduction in the fibre content after the enzymatic treatment. The application of 0.025% of pectinase with 0.075% of cellulase caused a greater reduction in fibre content and hence a lower viscosity of the juice. At the same time, a minimum of 0.05% of Pectinex Ultra SP-L was required to obtain the lowest pectin concentrations. The combined application of these enzymes resulted in a lower viscosity juice whose rheological behaviour was close to Newtonian, and hence the Power Law model would be more suitable for use in mathematical modelling.

Enzymatic Treatment of Soft Jackfruit (Artocarpus heterophyllus) Pulp With Two Commercial Pectinases: Physical Properties and Viscosity Analysis

“…After enzyme treatment, pectin degradation leads to a reduction in water retention capacity, causing water to be released into the system, reducing juice viscosity (Lee et al, 2006). Enzyme treatment with pectinase was used to reduce viscosity of fruits such as pitanga -from 2.85 mPa.s to 1.78 mPa.s (Ongaratto & Viotto, 2015), guava -from 17.72 mPa.s to 0.969 mPa.s (Ninga et al, 2018) and bananas -up to 1.89 cps (Lee et al, 2006). According to Ninga et al (2018), this rheological property is reduced by enzyme depectinization, which degrades pectin and other pulp polysaccharides.…”