Effect of NaCl on the structural properties, hydrolytic properties and binding of heptanal of oxidized myofibrillar proteins

This study investigated the effect of NaCl concentration on the structural properties, hydrolytic properties, and flavor binding capacity of oxidized myofibrillar proteins (MPs). The interaction mechanism of oxidized MPs hydrolyzed by trypsin and heptanal was also explored by spectroscopic methods. The results indicate that increasing the NaCl concentration from 0.3 M to 0.6 M enhanced the oxidation reaction. This promoting effect on the oxidation of MPs was particularly pronounced when the H₂O₂ concentration was ≥10 mM. Moderate oxidation (with 1 mM H₂O₂) and an increase in NaCl concentration (0.3 M-0.6 M) promote the structural unfolding of MPs, thereby exposing additional sites and hydrophobic amino acids that facilitate hydrolysis by trypsin. The mechanism of interaction between oxidized MPs hydrolyzed by trypsin and heptanal was a combination of dynamic and static quenching, with hydrophobic interactions serving as the predominant driving force in this process. This research provides valuable methodological insights for improving the quality and flavor of fermented meat products.