Immobilization of Aspergillus oryzae with κ-carrageenan for soybean oligosaccharide hydrolysis

Abstract

The immobilized Aspergillus oryzae spores in κ-carrageenan were used for production of α-galactosidase. The immobilized cells could be used up to 5 repeated cycles for enzyme production. They were employed for raffinose family oligosaccharides (RFO) hydrolysis in batch, repeated batch, and continuous operations after 5 days of fermentation. In batch mode, 65, 73, and 80% of RFOs were hydrolyzed after 3, 6, and 12 h, respectively; in repeated batch; 70, 63, 52, and 45% were hydrolyzed in 1, 2, 3, and 4 repeated cycles. In the fluidized bed reactor, 65, 58, 53, 48, and 44% RFOs were hydrolyzed at flow rates of 25, 50, 75, 100, and 125 mL/h respectively. The κ-carrageenan beads maintain good mechanical strength up to 4 repeated uses for RFO hydrolysis in soymilk, and their use in the hydrolysis of RFOs of soybean is a promising solution to overcome flatulence and to increase consumption of soy products.