Extrusion process optimization for plant protein-based snack foods

Overview

This research program focuses on optimizing low-moisture twin-screw extrusion to produce high-quality plant protein-based snack foods. By systematically varying processing parameters such as zone temperature, screw speed, moisture content, and die geometry, the work investigates how thermo-mechanical treatments influence protein-protein and protein-carbohydrate interactions—both covalent and non-covalent—within the food matrix. The goal is to modulate textural and structural properties to improve eating quality and nutritional value of puffed snacks and high-protein bar products.

Technical specifications

Research approach:

• Quantifies processing intensity through specific mechanical energy and specific energy delivered to ingredients
• Correlates physicochemical changes in food proteins with glass transition temperature
• Evaluates texture attributes including hardness, crispness, bulk density, expansion index, water absorption index, and water solubility index
• Uses a Brabender TwinLab-F 20/40 Twin-Screw Extruder for parameter optimization across different plant protein sources
• Analyzes protein function-structure relationships from raw materials through to final extruded products, including in-line and finished product characterization

Key research insights:

• Moisture migration is identified as the decisive factor in high-protein bar hardening during storage
• Disulfide-induced protein aggregation contributes to bar hardening over time
• Substituting whey protein isolates with intact or hydrolyzed casein reduces bar hardening
• Physicochemical changes in protein dough systems relate to glass transition temperature

Technology readiness level

This is an active research and process optimization program at the early-to-mid stage of development. The team is establishing an extrusion model and determining optimal parameters for different plant protein-based snack formulations. Validation involves both in-line physicochemical analysis during extrusion and characterization of final product quality. The program seeks industry partnership with food manufacturers to supply ingredients and assess finished products, representing an opportunity for collaborative development toward commercially viable plant protein snack applications.