Preparation, selenium content and stability of antihypertensive peptides from selenium-enriched Moringa oleifera seed protein by enzymatic hydrolysis

Abstract

Objective: To develop selenium-enriched （Se-enriched） Moringa oleifera seed protein resources. Methods: Using Se-enriched Moringa oleifera seed protein powder as raw material, the enzymatic hydrolysis conditions of Se-enriched Moringa oleifera seed protein antihypertensive peptides from Se-enriched Moringa oleifera seed protein were obtained by single factor and response surface optimization, and the ACE inhibitory activity, Se content and stability of the optimal enzymatic hydrolysate were analyzed. Results: The optimal enzymatic hydrolysis conditions of Se-enriched Moringa oleifera were as follows: enzymatic hydrolysis time 3 h, temperature 34 ℃, pH 8, concentration of substrate 7%, enzyme to substrate ratio 0.3%. Under these conditions, the semi-inhibitory concentration of ACE of the peptides was 1.956 mg/mL. The Se content of the antihypertensive peptide was 1.394 mg/kg, which was 1.1 times that of the raw protein. Moreover, the antihypertensive peptides （5 mg/mL） had good thermal stability and acid-base stability, and could still maintain good ACE inhibitory activity after digestion by gastrointestinal enzyme system in vitro. Conclusion: The Se-enriched Moringa oleifera seed protein antihypertensive peptides obtained by response surface optimization showed strong ACE inhibitory activity and good stability.

Keywords

• selenium-enriched moringa oleifera seed
• enzymolysis
• antihypertensive peptide
• angiotensin converting enzyme (ace) inhibitory activity
• selenium content
• stability