Preparation And Antioxidant Activity Of Protein Hydrolyzate From

The queen bee larvae has rich nutritional value and many other advantages in medical field such as improving human immunity and the ability of the anti-aging, anti-fatigue and antioxidation. Because of its high production and better performance in medical care the queen bee larvae becomes one of the greatest insect resource. This paper set the queen bee larvae as a research goal and the conventional physical and chemical indicators (moisture, ash, protein, etc.) are measured by the standard reference methods. Meanwhile, the queen bee larvae proteins hydrolysates were optimized by the single factor experiment and response surface methods. Peptides derived from queen bee larvae protein hydrolysates were separated by Ultrafiltration (UF) and Gel Filtration Chromatography (GFC). Its hydrolyzed conditions and antioxidant peptide components as well as antioxidant ability of its hydrolyzate were studied. The results list as follows:1. The total value of queen bee larvae protein was62.18%. Carbohydrate contained was9.36%, and the percentage of fat was25.8%.Then the content of ash was1.16%. At last the queen bee larvae fatty acid composition was determined by gas chromatography test and the results show that the total number of the saturated fatty acid is56.81%.2. The level of proteolysis bout the queen bee larvae which is generating from alkaline protease hydrolysis is highest one and the strongest radical scavenging capacity towards DPPH. Under this situation, the optimum conditions of hydrolysising the alkaline protease about queen bee larvae is listed as follow: pH9.7, reaction temperature51℃, enzymolysis time180min, enzyme amount4%, DH3.73%.3. Seprately through the ultrafiltration membrane of1KDa and5KDa, the queen bee larvae protein enzymolysis liquid turned into other enzymolysis production with a different molecular weight range. The one within1KDa had the most mount of production and the strongest antioxidant activity.It provided the figure about DPPH radical scavenging activity IC50was21.86mg/ml, and the reducing power for Fe3+was2.787mmol FeⅡ/g polypeptide and the iron chelation was0.41mg Na2ETDA/g polypeptide. 4. After using the Sephadex G-15to analysis the protein dydrolyzate production of the queen bee larvae which was below lkDa molecular weight range, we obtained4peaks at the result image. Obviously, Peak4which contained IC50of the DPPH radical scavenging activity had the strongest antioxidant activity among them. Futhermore, In Peak4, the reducing power for Fe3+was7.592mmol FeⅡ/g polypeptide and the iron chelation was0.5mg Na2ETDA/g polypeptide.