Improving the Solubility of Myofibrillar Proteins (MPs) by Mixing with Sodium Alginate: Effects of pH, Mixing Ratios and Preheating of MPs

Myofibrillar proteins (MPs) are underutilized because of their weak solubility in low-salt conditions. In this research, mixing MPs with sodium alginate (SA) was studied to improve the solubility of MPs, and the effects of pH, mixing ratios (r), and protein preheating were examined. Mixing with SA improved the solubility of MPs at pH 6.5 and 5.5, and the precipitation of MPs was completely inhibited by an MPs/SA ratio of 20 and 5.0, respectively. The solubility of MPs was not improved by mixing with SA at other pHs. The mixing behavior of MPs and SA was greatly influenced by the electrostatic interaction, depletion interaction, and bridging flocculation. Preheating MPs (70 °C, 30 min) reduced the amounts of SA required to inhibit their precipitation and improved the heat stability of MPs/SA mixtures. These improvements may have resulted from the exposure of embedded negatively charged groups, decrease of particle size in MPs, and disulfide crosslinking after preheating. These findings demonstrate an approachable route to obtain soluble forms of MPs, which may find application in liquid products.