Synergistic compensation of low salt induced quality defects in low-salt tomato canned beef by acetic acid and L-aspartic acid: pH and charge induced hydrogen bond enhancement.

This study investigated the effects of a combined acetic acid (HAc) and L-aspartic acid (L-Asp) treatment on the quality of low-salt (0.4% NaCl) tomato-canned beef. The shear force values decreased by 46.42% and 40.03% compared with the normal-salt and low-salt control groups, respectively, demonstrating a substantial improvement in meat tenderness. The reduction in pH, coupled with electrostatic interaction mediated by L-Asp, synergistically altered the conformation of myofibrillar protein (MP). These conformational changes were characterized by enhanced hydrogen bonding, a decrease in β-sheet content, and a significant increase in β-sheet (p < 0.05). Further pH reduction induced by HAc increased the net positive charge of MP, expanded myofibrillar gaps, and increased thiol content. In combination with weak-acid-induced stimulation, these changes also contributed to an enhancement in perceived saltiness. The synergistic application of both approaches addresses beef quality issues, providing a theoretical foundation for the development of reduced‑sodium meat foods.