Concentration-dependent gelation, water-holding, and emulsifying performance of soybean peptide-hawthorn pectin Maillard hydrogels.

Abstract

This study examined the concentration-dependent gelation and structural evolution of heat-induced hydrogels prepared from soybean peptide-hawthorn pectin Maillard reaction products (SBP-HP MRP). With increasing concentration, the system shifted from molecular association to network formation. Rheological measurements showed weak gel formation at approximately 9.0 mg/mL, whereas vial inversion identified 9.5 mg/mL as the self-supporting gel concentration. From 9.0 to 12.0 mg/mL, apparent cross-linking density increased from 3.54 to 6.63 mol·m - 3, and mesh size decreased from 73.58 to 50.84 nm, indicating progressive network densification. Avrami analysis and DLS suggested faster aggregate growth and larger aggregates at higher concentrations. Functional evaluation identified 11.0 mg/mL as the optimal concentration, showing high water-holding capacity (94%), EAI (≈34 m2/g), OHC (18%), and balanced texture. Excessive concentration increased rigidity but weakened functional performance. These findings clarify structure-function relationships in SBP-HP MRP hydrogels and support formulation design for texture-modified foods and delivery systems.