Abstract:

The conditions for the two-stage enzymatic hydrolysis of grass carp protein were optimized by means of the Response Surface Methodology(RSM).In the first stage of hydrolysis,pancreatin and flavorzymes in a mass ratio of 4:1 were used together and protein recovery was chosen as the response value,while in the second stage,papain was used and peptide recovery was chosen as the response value.A mass ratio of E(enzyme)to S(substrate)
of 0.30:100,a hydrolysis temperature of 53 ℃ and a hydrolysis period of 5.90h were then treated as the op-timal conditions for the first stage,and a mass ratio of E to S of 0.12:100,a hydrolysis temperature of 60℃ and a hydrolysis period of 5.60 h were determined for the second stage.In the above.mentioned optimal conditions,the relative molecular mass of the hydrolysates is between 714 and 8790.and the mass fraction of peptides is more than 50% ,which is consistent with the value of 52,55% predicted by the RSM.All these conclusions aYe proved by the results of gel filtration chromatography.

Key words: Response Surface Methodology, grass carp, protein, enzymatic hydrolysis, polypeptide