Effects of degree of hydrolysis (DH) on the functional properties of egg yolk hydrolysate with alcalase.

Effects of enzymatic hydrolysis on the physicochemical and functional properties of egg yolk were investigated in this study. Alcalase, neutrase and flavourzyme were used to hydrolyze egg yolk. Solubility, foaming properties, emulsifying and microstructure properties of egg yolk were determined after enzymatic hydrolysis. Results showed that alcalase had better efficiency of hydrolysis than neutrase and flavourzyme. Enzymatic hydrolysis caused a marked changes in protein solubility, surface hydrophobicity, molecular weight distributions, microstructure and other functional properties. It was observed that egg yolk and its hydrolysates exhibited a relatively smooth curve over the entire pH range; egg yolk hydrolysates with high DH had higher solubility than those having lower DH. Foam capacity and stability generally increased with increasing DH although foam stability showed a decrease at 15% DH. Hydrolysates of egg yolk showed scattered and fewer aggregated particles. This study demonstrated that egg yolk hydrolysates could be an excellent emulsifying agent for food and other applications.