Production of Angiotensin I Converting Enzyme Inhibitory Peptides from Peanut Meal Fermented with Lactic Acid Bacteria and Facilitated with Protease

The aim of this study was to develop a simpler and cheaper technique using a combination of Lactic Acid Bacteria (LAB) fermentation and protease hydrolysis to accelerate the production of bioactive peptides in peanut meal. Firstly, peanut meal was fermented with a total of 14 LAB strains to assay in vitro Angiotensin I Converting Enzyme (ACE) inhibitory activity and Degree of Hydrolysis (DH). Among the strains used, Lactobacillus plantarum Lp6 was selected for further studies because of its highest ACE inhibitory activity (47.83±4.92%) and DH of protein (2.29±0.51%). The addition of protease during the fermentation could highly improve the soluble protein, DH and ACE inhibitory activity of peanut meal. Molecular weight distribution analysis revealed the Extracts from Fermented Peanut Meal (EFPM) was mainly composed of oligopeptides. The ACE inhibitory activity of EFPM remained stable after pepsin and pancreatin treatments simulating an in vitro gastrointestinal digestion. Furthermore, the EFPM exerted potent antihypertensive effect in Spontaneously Hypertensive Rats (SHR) after oral administrations at a dose of 200 or 500 mg/kg body weight. In conclusion, the peanut meal fermented with L. plantarum Lp6 and facilitated with protease could serve as a useful antihypertensive product in the prevention and treatment of hypertension.