Functionalization of Enzymatically Treated Apple Pomace from Juice Production by Extrusion Processing

Area of Science:

• Food Science and Technology
• Biopolymer Modification
• Sustainable Food Ingredients

Background:

• Food by-products like apple pomace are sustainable resources for novel ingredients.
• Technofunctional properties of food ingredients often require modification for specific applications.
• Enzymatically treated apple pomace presents potential but needs optimized processing.

Purpose of the Study:

• To investigate the impact of twin-screw extrusion processing on the technofunctional properties of apple pomace.
• To understand how varying thermomechanical conditions affect apple pomace composition and polymer structure.
• To determine the optimal extrusion parameters for improving apple pomace as a food ingredient.

Main Methods:

• Lab-scale twin-screw extrusion of enzymatically treated apple pomace under varied screw speeds and configurations.
• Comprehensive chemical and functional analyses (water absorption, swelling, viscosity, solubility index).
• Microstructural analysis using scanning electron microscopy and detailed dietary fiber polysaccharide analysis.

Main Results:

• Moderate extrusion conditions improved water absorption, swelling, and viscosity.
• Increased thermomechanical stress led to higher water solubility but reduced water absorption, viscosity, and swelling.
• Extrusion disrupted cell wall structure and increased soluble dietary fiber content from 12.6 to 17.2 g/100 g dry matter.
• Pectin polysaccharides, particularly arabinans, were susceptible to degradation under high thermomechanical stress.

Conclusions:

• Twin-screw extrusion is effective in modifying apple pomace for improved functionality, especially increasing soluble fiber.
• Careful control of thermomechanical conditions is crucial to avoid degradation of valuable polysaccharides like pectin.
• Optimized extrusion processing can enhance the value of apple pomace as a sustainable food ingredient.