Research of frog antioxidant peptide and the activity of gastrointestinal digestion

The frog protein hydrolysates were prepared by alcalase, papain, pancreatin and Flavourzyme, and the properties of hydrolysates and their antioxidant activities were studied.Results showed that the use of papain and flavourzyme together could get better antioxidant capacity, better hydrolysate degree, and protein recovery;and the amid acid composition of the hydrolysate also was outstanding, the values of EAA /TAA (45.06%) and EAA / NEAA (82.01%) were both higher than the FAO /WHO recommendation.The profile of molecular weight distribution revealed that the molecular weight less than 3000u reached 73%, while only 3% was observed for molecular weight more than 10000u.The antioxidant activities of frog peptide were all changed during the gastrointestinal digestion, a significant increase was saw during 0 ~ 0.5h (p < 0.05) , while during 2.5 ~ 4.0h, no significant changes were inspected.