Study on the optimization for enzymatic hydrolysis and physicochemical properties of egg white protein

• 1、 Food Science College of Jiangnan university, Wuxi, Jiangsu 214122
• 2、Food Science College of Jiangnan University,Wuxi,Jiangsu 214122

Abstract：Egg white contained a variety of proteins. Moderate enzymatic hydrolysis of egg white protein helped improve foaming properties. So, the physicochemical properties of the hydrolysates, obtained by hydrolysis with papain from fresh egg white were characterized. Taking foaming ability, foam stability and degree of hydrolysis as indicators, the enzymatic hydrolysis parameters of egg white protein were optimized by single factor experiments. The optimum enzymatic hydrolysis conditions: substrate concentration 4%, enzyme dosage 1250 u/g, hydrolysis time 120 min, hydrolysis temperature 55℃ and pH 7.0. Under these conditions, the foaming ability, the foam stability and the degree of hydrolysis of egg white protein were 2844.70%, 89.57%and 8.08%. Compared with the fresh egg white protein, the foaming ability and foam stability of modified protein were increased by 2.68 times and 0.9 times respectively. The results of physicochemical properties of the hydrolysates showed that Surface hydrophobicity was increased by 4.46 times , beneficial to the improvement of the foam stability, and the content of molecular weight of peptides is the largest in a range of 1000-5000Da, which could form a stable system in the gas-liquid interface.

Keywords： Papain egg white protein foaming characteristics degree of hydrolysis physicochemical properties