Calcium Alginate Entrapped Preparation Of Alpha-Galactosidase: Its Stability And Application In Hydrolysis Of Soymilk Galactooligosaccharides

Thermostable alpha-galactosidase from Aspergillus terreus (GR) was insolubilized using concanavalin A obtained from jack bean extract and in order to maintain the integrity of complex in the presence of its substrate or products, this complex was crosslinked with glutaraldehyde. Soluble alpha-galactosidase entrapped in calcium alginate retained 82% of enzyme activity whereas, Con A-alpha-galactosidase complex entrapped in calcium alginate and crosslinked Con A-alpha-galactosidase complex entrapped calcium alginate retained 74 and 61% activity, respectively. A fluidized bed reactor was constructed for continuous hydrolysis of galactooligosaccharides in soymilk using crosslinked Con A-alpha-galactosidase complex entrapped calcium alginate. Optimum conditions such as pH (5.0) and temperature (65A degrees C) were the same for all immobilized enzyme preparations and soluble enzyme. Crosslinked Con A-alpha-galactosidase entrapped complex exhibited enhanced thermostability and showed 62% of activity (38%) after 360 min at 65A degrees C. Entrapped crosslinked Con A-alpha-galactosidase complex preparation was superior in the continuous hydrolysis of oligosaccharides in soymilk by batch processes compared to the other entrapped preparations. The entrapped crosslinked concanavalin A-alpha-galactosidase complex retained 95% activity after eight cycles of use.