Abstract
A mixed system with a 5:1 ratio of beef myofibrillar protein to type I collagen was prepared to mimic meat broths. The study aimed to determine the combined effects of various NaCl concentrations (0, 0.2 M, 0.4 M, 0.6 M) and heat treatment on solubility, emulsifying properties (EAI, ESI), viscosity, and particle size of the mixed protein system. Mechanistic changes were examined through molecular interactions, intrinsic fluorescence, protein molecular weight, and Raman spectroscopy. The results showed that, without heat treatment, NaCl enhanced solubility, EAI, ESI, emulsion viscosity, and hydrogen bonding. After heating (90 °C, 30 min), elevated 0.4-0.6 M NaCl created an unstable, crowded environment, resulting in protein aggregation and reduced solubility and emulsifying performance. The results indicated that heating at 90 °C with 0.2 M NaCl was beneficial for meat emulsification, providing valuable production guidance for optimizing the formulation of meat products with low salt and high emulsifying properties.