Antihypertensive Bioactive Peptides from Hydrolysates of Soy milk Yoghurt (Soygurt)

Abstract

Soyghurt is a product of fermented soy milk which beneficial nutrients and functional food. This study was conducted to isolate and characterize bioactive peptides from soyghurt hydrolysates which potential as antihypertensive drugs. Soyghurt precipitated by the addition of HCl 1M and centrifuged. Pepsin as a proteolytic enzyme was used to hydrolyzed soygurt with enzyme/substrate ratio (1/20) at 37 °C and pH 4.5 by interval of hydrolysis time 2, 4, 8 and 16 hours. The quantity of protein hydrolysates determined by Lowry method and the peptide pattern analyzed by SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis). Antihypertensive activity of soyghurt hydrolysates determined by angiotensin converting enzyme (ACE) inhibitory assay. Protein hydrolysates with the highest inhibition capacity purified by gel filtration column G-15. The results of this study show that soygurt hydrolysates with the highest of ACE inhibition obtained by 16 hours of hydrolysis with the highest degree of hydrolysis (51.6%) and antihypertensive activity 90.2%. This soygurt hydrolysates could potentially be used as natural antihypertensive agent.