Optimization of Enzymatic Hydrolysis of Bee Pollen Protein by Pepsin Based on Antioxidant and ACE Inhibitory Activity and Comparison with Those of Royal Jelly

In this study optimization of the enzymatic hydrolysis condition of bee pollen protein by pepsin and the effect of enzymatic hydrolysis on its antioxidant properties was investigated. Also, the results were compared with antioxidant properties of royal jelly. For this purpose, phenolic compounds, DPPH free radical scavenging activity and ferric ion reducing power of bee pollen and royal jelly were measured. The values of these factors for bee pollen and royal jelly (1000 ppm), were 174 and 1031.71 (mg Gallic acid/ g sample), 67.33% and 95.27% and absorbance of 0.77 and 0.8 at 700 nm, respectively. The highest reducing power of 0.81 was measured in samples which were hydrolyzed by 2% pepsin for 4 h. Also, the highest DPPH radicals scavenging power was 100% which was achieved in hydrolyzed samples by 2% pepsin for 2.5 h. The highest ACE inhibitory activity was 91.49% in hydrolyzed samples by 2% pepsine for 4 h. The results showed that the DPPH radical scavenging power of bee pollen increased from 67.33% to 100% and ACE inhibitory activity increased from 15.54% to 91.49% after enzymatic hydrolysis. The DPPH radical scavenging power and ACE inhibitory activity of bee pollen hydrolysats were comparable to those of royal jelly.