Impact of pH-dependent succinylation on the structural features and emulsifying properties of chicken liver protein

This work aims at investigating the pH-regulated relationship between the structural features and emulsifying properties of chicken liver protein (CLP) during succinylation and related mechanisms behind. The results demonstrated that the major succinylation sites occurred at lysine, histidine and tyrosine of CLP, and the succinylation degree increased by 30.66% as pH increased to 10. The succinylation pH elevation increased the solubility and oil absorption capacity of CLP, thus favoring its improvement in emulsifying properties, due to the succinylation process-induced increase in surface charge density and amphiphilic balance as well as modified network structure. However, the surface hydrophobicity of succinylated products decreased by 10.75% when the pH increased from 7 to 10. Besides, succinylation-induced variations in electrostatic repulsive and particle size distribution greatly improved the storability of the emulsions. These results suggested the great potential of pH-modulated succinylation to regulate the structure–property relationship of protein-based products.