Probing multiscale structure of plant protein-based food system: Application of small-angle X-ray and neutron scattering (SAXS/SANS)

Abstract

Plant-based foods are gaining momentum as sustainable and health-conscious alternatives to animal-derived products. Understanding the structural organization of plant protein systems from molecular to mesoscopic scales is essential for designing products with desirable texture, stability, and nutritional performance. Small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) are powerful, non-destructive techniques that provide detailed insights into the hierarchical structures of these systems under realistic, hydrated conditions. This review summarizes recent advances in the use of SAXS and SANS to study plant-based gels, foams, emulsions, meat analogues, dairy alternatives, and in vitro digestion. These techniques reveal critical information on protein aggregation, network formation, interfacial structuring, and digestion dynamics, often inaccessible by conventional methods. We also outline future research directions, including expanding to non-thermal gelation pathways, integrating in situ processing environments, coupling with complementary techniques, and leveraging AI for structural interpretation. SAXS and SANS are poised to play a central role in the rational design of next-generation plant-based foods with optimized functional and sensory attributes.