Enzymatic Hydrolysis and Composition Analysis of Polypeptide from Eggshell Membrane

Abstract Eggshell membrane, also called “ Feng Huang Yi ” in traditional Chinese medicine, is a protein-based fibrous tissue and has various biological functions. This study aims to obtain an optimal condition for preparing eggshell membrane peptides (ESMP) using alkaline protease. Then the free and protein amino acid compositions, and the molecular weight distribution of the ESMP were analyzed in order to investigate the effect of enzymatic hydrolysis. Through single factor experiments and orthogonal optimization, the optimal condition for preparing ESMP was obtained. Under the conditions of enzyme dosage 13,000 U/g, hydrolysis time 6.5 h, and solid-liquid ratio 1:35, the hydrolysis degree was 62.10%. The top five predominant protein amino acids in ESMP were Glu, Asp, Pro, Cys and Arg, and the predominant free amino acids in ESMP were Met, Val, His and Cys. The content of peptides below 10,000 Da in ESMP was 98.07%.