Ultrasound-assisted heat-induced gelation properties of potato protein - carboxymethyl chitosan complexes: modulation...

This study systematically investigated the gelation behavior of potato protein (PP) - carboxymethyl chitosan (CMCS) composite gels under varying pH (3.0, 6.0, 10.0) and ionic strengths (0 mol·L^-1, 0.1 mol·L^-1, 0.3 mol·L^-1 CaCl₂). The results demonstrated that under pH 6.0 and 0.1 mol·L^-1 CaCl₂ conditions, electrostatic repulsion between PP and CMCS was weak, while hydrogen bonding and hydrophobic interactions dominated. The resulting gels exhibited a lower zeta potential, higher turbidity, and improved water-holding capacity. The protein secondary structure showed increased content of α-helix and β-sheets, enhanced thermal stability, and superior hardness and cohesiveness. Rheological analysis further confirmed a higher storage modulus, indicating improved elasticity and structural integrity of the gel network. Microscopic observations revealed the formation of a denser and more uniform gel structure under these conditions. These findings provide a theoretical foundation for the development and application of PP-CMCS composite gels as novel plant-based materials.