Abstract: Allolobophora caliginosa trapezoides (Duges 1828) in Xinjiang was hydrolyzed by papain and Alcalase 2.4L respectively, and amino acid content of enzymatic hydrolysates of A.caliginosa trapezoides were studied. The optimum conditions of enzymatic hydrolysis were determined with amino acid content of A. caliginosa trapezoides as index for investigation through single-factor analysis and orthogonal test L9(34), as follows: temperature 50℃, pH 7.5, time 8 hours and enzyme concentration 0.3% by papain, as well as temperature 50 ℃, pH 7, time 8 hours and enzyme concentration 0.3% by Alcalase 2.4L of A.caliginosa trapezoides substrate protein. Under these conditions, the amino acid content of enzymatic hydrolysates can reach 16.55 mg/ml and 29.48 mg/ml, respectively. The efficiency of enzymatic hydrolysis of Alcalase 2.4L is higher than that of papain. These results indicated that Alcalase 2.4L is more suitable for produce small peptides enriching amino acids and trace elements.

Key words: Allolobophora caliginosa trapezoides, papain, Alcalase 2.4L, amino acid, comparative analysis