Abstract: In this study, compound gels of polyvinyl alcohol (PVA)-calcium alginate were chosen as the insoluble carrier to
immobilize naringinase crosslinked with glutaraldehyde. The results showed that adding glutaraldehyde and delay embedding
were more effective than the other methods. The optimal conditions for naringinase immobilization were obtained as followings:
PVA at 9.0 g/100 mL, sodium alginate 1.0 g/100 mL, CaCl2 1.0 g/100 mL, and enzyme concentration at 2.0 mg/mL, and the
immobilization time for 10 h. In addition, the characteristics of free and immobilized naringinase were further investigated. The
optimal pH value and temperature of immobilized enzyme were not changed, but a better thermal stability and storage stability
were observed for immobilized one. Immobilized naringinase could be recycled six times to hydrolyze naringin and still retained
more than 60% activity.

Key words: polyvinyl alcohol (PVA), calcium alginate, immobilize, naringinase