Abstract:

In this study, Mucor mucedo MHC-7 was cultured in fermentor for producing sufu. During the fermentation, the change of enzyme activity and chemical composition of sufu were investigated. The results showed that: the best fermentation time of MHC-7 in fermentor is 30 h; the activity peak time of protease, α-amylase, α-galactosidase, glutaminase, cellulase, lipase, glucoamylase and pectolase in soybean billet is 48, 36, 48, 48, 66, 36,30 and 72 h; except α-galactosidase activity increasing, the activities of the other enzymes decrease; and the contents of crude protein, crude fat and reducing sugar decline with fermentation time extending, but the contents of amino nitrogen, free fatty acids and total acid increase unceasingly. In conclusion, α-galactosidase activity ≥ 86.3 U/g, total acid content ≥ 1.0%, amino nitrogen content ≥ 0.45%, sugar content ≤ 1.1% and viscosity ≤ 2 × 105 mPa·s can be taken as the signs of maturity of sufu.

Key words: MHC-7, fermentor culture, enzyme activity, chemical composition