Optimization of the conditions for immobilization of crude pectinase on chitin using ultrasound and glutaraldehyde and its application in grape juice clarification

Abstract

The current research focuses on optimizing the immobilization of crude pectinase, produced by solid-state fermentation, onto chitin using ultrasound and glutaraldehyde as a crosslinking agent for grape juice clarification. A Box-Behnken design was used to model the effects of ultrasound time (5–15 min), ultrasound amplitude (20 – 60 %), and water-to-support ratio for ultrasound application (16−24) on immobilized crude pectinase activity and immobilization efficiency. Optimal conditions, comprising ultrasound time of 10 min, ultrasound amplitude of 20 %, and water-to-support ratio for ultrasound application of 24, yielded an immobilized crude pectinase activity of 2.19 IU/mL and 74 % immobilization efficiency. The immobilized crude pectinase showed improved kinetic properties and retained 69 % activity after three use cycles. Both free and immobilized crude pectinase enhanced juice clarity, reducing sugar, and TSS while lowering viscosity.