Engineered plant protein-starch-fibre matrix for low-moisture extruded snack textures

Overview

This research program addresses a central challenge in plant-based food innovation: producing expanded, high-protein snacks with desirable texture and quality. The work investigates how temperature-induced denaturation and shear-induced defragmentation of plant proteins interact with residual fibre and added starch during low-moisture extrusion. By understanding and engineering these ternary interactions, the team aims to establish design rules for expanded protein snacks with variable, predictable structures.

The approach has practical value for food manufacturers, ingredient suppliers, and snack product developers seeking to expand their plant-based portfolios with texturally competitive offerings. Applications include high-protein extruded snacks, meat analogue textures, and ingredient systems where protein content, expansion ratio, and mouthfeel are critical product attributes.

Technical specifications

Core mechanism:

• Protein unfolding during extrusion exposes reactive sites that form intra- and intermolecular disulphide bonds, hydrophobic interactions, and hydrogen bonds with fibres present in protein concentrates and with added starch
• Shear-induced scission of protein, starch, and fibre macromolecules enhances interfacial interaction among the three components
• Control of temperature, pressure, screw speed, feed rate, and feed composition modulates the degree of ternary interaction and resulting extrudate structure

Characterization capabilities:

• Protein analysis using SEC, RP-HPLC, CD, DSC, and FTIR
• Starch and fibre molecular weight profiling using GPC
• Microstructure imaging using SAXS/WAXS, confocal microscopy, and SEM
• Physical and sensory property testing for texture, porosity, and consumer-relevant attributes

Feedstock scope:

• Protein isolates from pea, soybean, faba bean, and lentil
• Variable ratios of protein, starch, and fibre to map structure-property relationships

Technology readiness level

The program is at an early-to-mid experimental stage. Preliminary results at Monash University indicate that the degree of shear scission of macromolecules and the ratios of protein, starch, and fibre are primarily responsible for the structure of both expanded and non-expanded extruded products. Ongoing and planned validation will systematically vary processing parameters and ingredient composition across multiple plant protein sources, with comprehensive molecular, microstructural, and sensory characterization to establish design rules for high-protein expanded products. The work is positioned for collaboration with ingredient suppliers and snack manufacturers interested in co-developing plant-based extruded products.