Preparation,Hypoglycemic and Antioxidative Activity of Peptide from Royal Jelly Protein

Objective:To optimize the enzymatic hydrolysis conditions of royal jelly protein,and analyze the amino acid composition,molecular weight distribution,hypoglycemic and antioxidant activities of the hydrolyzed peptides. Methods:Taking royal jelly as raw material,the royal jelly protein was extracted using alkali-extracting method. Screening the optimal protease for enzymatic hydrolysis of royal jelly protein was carried out with α-glucosidase inhibition capacity and ABTS free radical scavenging rate as indicators. The hypoglycemic and antioxidant activities in vitro of royal jelly peptide prepared under the optimal conditions were also evaluated. Results indicated that the optimal conditions for preparing hypoglycemic and antioxidant peptide were as follows:Acid protease,emzyme-protein ratio of 6000 U/g,enzymolysis temperature of 43℃,enzymolysis pH of 4.0,enzymolysis time of 4 h,liquid-to-material of 1:10. Under above conditions,the total amino acids content of obtained royal jelly peptide was 82.19%,and the relative molecular weight was less than 1000 Da. The IC₅₀ value of royal jelly peptide for α-glucosidase inhibition capacity was 6.94 mg/mL. The IC₅₀ values of royal jelly peptide for ABTS,hydroxyl,DPPH and superoxide anion radicals scavenging ability were 14.18,0.45,11.02 and 18.38 mg/mL,respectively. Results indicated that the royal jelly peptide exhibited hypoglycemic and antioxidant activity. Thus,it can provide theoretical basis for high value utilization of royal jelly and development of active peptide products.