Effect of enzymes on the degree of maceration of soybean fermented by Rhizopus Strains

Abstract

Relationship between the degree of maceration (given in n-value) of fermented soybean and macerating enzyme formation was observed on raw and sterilized soybeans fermented for 12, 24, 36 and 48 h at 30°C with 7 Rhizopus strains. Among 7 Rhizopus strains tested, Rhizopus oligosporus (TISTR3001, known as a dominant tempeh processing strain) gave the most powerful maceration degree (n-value in the equation, F=C(Δε)n) of n=1.4 (initial value of 1.8) and n = 1.1 (initial value of 1.7) for raw and sterilized soybeans respectively, for 48 h of fermentation. Enzyme activities such as cellulase, pectinase, amylase and protease, markedly related to the degree of maceration. Among the enzyme formation, particularly both pectinase and cellulase gave the powerful maceration effect on the soybean fermented with Rhizopus since the formation of both enzymes coincided with the decrease of n-value.