FABRICATION OF IMMOBILIZED MULTI-ENZYME SYSTEM IN GLUTARALDEHYDE ACTIVATED GELATIN BLOCKS TARGETING THE QUALITY AND YIELD OF APPLE JUICE

Driven by rising consumer demand for nutritionally beneficial and high-quality fruit juices, the present study employed enzyme technology to improve the yield and quality of apple juice. Pectinase and Cellulase were produced from locally isolated Bacillus sp. AA-04 and Bacillus sp. SM-07 and partially purified using salt fractionation technique. Maximum activity of Pectinase was found at 5 minutes, 50 °C, and pH 7.5. Cellulase required 10 minutes, 55 °C, and pH 8.0 for its optimal activity. The Vmax and Km were 497 U/mL and 0.115 mg/mL for Pectinase, whereas, Cellulase exhibited Vmax 370.4 U/mL and Km 0.1177 mg/mL. Apple pulp pretreated with soluble Pectinase and Cellulase at 40 °C for 45 minutes resulted in 57.89 % increase in juice yield. Multi-enzyme immobilized gel blocks fabricated from 30 % gelatin (w/v) and 20% (v/v) glutaraldehyde were used for juice clarification. The reduction in the viscosity and turbidity of apple juice were observed by 35% and 55% respectively as compared to raw juice, at 50 °C after 45 minutes of treatment. The multi-enzyme gel blocks were reused for 6 operational cycles of juice clarification.