Preparation Of Millet ACE Inhibitory Peptide And Its Antihypertensive Activity

As a common cereal,millet has a long history of eating in China.Because of its rapid growth rate,wide adaptability,drought tolerance,storage resistance and low price,millet is widely planted by laborers.Therefore the edible and medicinal value of millet has a broader development space.Millet has a high protein content and a wide range of amino acids and is suitable for the preparation of plant active peptides.In this study,millet peptides with ACE inhibitory activity and antioxidant activity were prepared by enzymatic hydrolysis.In this study the millet protein was extracted by alkali-soluble acid precipitation method and the millet protein was hydrolyzed by alkaline protease,neutral protease,papain and trypsin.According to enzymatic product inhibition rate of ACE and hydrolysis degree choose neutral protease as enzymatic solution,and enzyme reaction time was 180 min.The enzymatic hydrolysates pass through molecular weight of 1 KD and 3 KDa ultrafiltration membranesby in turn,obtained three components MPH-P_1,MPH-P₂ and MHP-P₃.The ACE inhibition activity and DPPH radical scavenging activity of the three ultrafiltration products were determined and it was found that MPH-P₁ had the best ACE inhibitory peptide activity and antioxidant activity.The amino acid composition and Q-TOF analysis of the three components were carried out for amino acid sequence and polypeptide sequence analysis.HUVECs were treated with hydrogen peroxide?H₂O₂?to establish an oxidative stress-induced cell injury model.After treatment of HUVECs with different concentrations of H₂O₂ cell viability decreased significantly in a dose-dependent manner.After treatment with different components of millet peptide H₂O₂-induced cell MDA content and total SOD activity were significantly decreased.The results showed that millet peptide could improve the damage of human umbilical vein endothelial cells induced by H₂O₂ and provide a basis for the deep processing of millet peptides and the development and utilization of functional foods.