Physicochemical characteristics and gel-forming properties of myofibrillar protein in an oxidative system affected by partial substitution of NaCl with KCl, MgCl2 or CaCl2

Effects of partial substitution of NaCl with KCl, MgCl 2 or CaCl 2 on oxidative characteristics of myofibrillar protein (MP) in a hydroxyl radical generating system and their heat-induced gel properties were investigated. Results indicated that MP oxidation is dependent upon the different chloride salt types and substitution degree. MP at 0.60 M NaCl was beneficial to protein unfolding and gel quality in the oxidative system. Increased formation of disulfide bonds affected the MP conformation and resulted in a large particle size and an aggregated   network   of   gel at the 50% substitution degree of KCl. The presence of CaCl 2 or MgCl 2 substitutes contributed to protein polymerization and insolubility. MP aggregation restrained the formation of dense and continuous gel networks during heating, and thus resulted in a low-grade gel. Ca 2+ had more serious impact on gel properties than Mg 2+ , dependent on different cation effects. Substitution of 25% NaCl by KCl gave acceptable gel quality in MP.