Apple juice clarification by immobilized pectolytic enzymes in packed or fluidized bed reactors

Area of Science:

• Biocatalysis
• Enzyme Immobilization
• Food Processing

Background:

• Pectic enzymes are crucial for juice clarification and processing.
• Immobilization of enzymes enhances stability and reusability.
• Optimizing enzyme support and reactor design is key for industrial efficiency.

Purpose of the Study:

• To evaluate the catalytic efficiency of pectic enzymes immobilized on various supports.
• To determine the optimal support material and reactor configuration for pectin hydrolysis.
• To analyze the kinetic parameters and performance of immobilized enzymes in apple juice processing.

Main Methods:

• Covalent immobilization of pectic enzymes onto glass microspheres, nylon 6/6 pellets, and PAN beads.
• Analysis of pectin hydrolysis kinetics using parameters like rate constant, time for 50% viscosity reduction (τ50), and complete depectinization time (τcomp,dep).
• Comparison of packed bed and fluidized bed reactor performance with real apple juice under optimized conditions (pH 4.0, 50°C).

Main Results:

• PAN beads demonstrated the most effective catalytic system for pectin hydrolysis.
• Fluidized bed reactors significantly outperformed packed bed reactors at higher circulation rates.
• Complete pectin hydrolysis was achieved 0.25 times faster in fluidized reactors (41 min) compared to packed reactors (131 min).

Conclusions:

• PAN beads are a highly effective support for immobilizing pectic enzymes.
• Fluidized bed reactors offer a substantial advantage for pectin hydrolysis in continuous apple juice processing.
• Optimized enzyme immobilization and reactor design can significantly improve the efficiency of juice depectinization.