Peptide with hydrophobic amino acids had been studied for their inhibitory activity against angiotensin-I converting enzyme (ACE-1) transformation into ACE-2 and prevention of hypertension. The active peptides may come from alcalase and flavourzyme hydrolysis of bean protein. This study aimed to measure ACE-1 inhibitory of protein hydrolysates from Vigna sp. bean (mung bean and cowpea) that grew in Indonesia, and its solubility. The bean protein (22.9 - 23.6 %) was extracted using isoelectric precipitation at pH 4-4.6. The extracts were hydrolyzed at pH 8 for alcalase and pH 7 for flavourzyme, followed with inactivation at 80-85 oC. ACE-1 inhibitory activity was calculated based on the amount of hippuric acid (HA) formed by the hydrolysis of Hippuryl-His-Leu (HHL), in spectrophotometry detection method (228 nm). Ultrachromatography evaluation showed that the protein hydrolysates of mungbean contained higher hydrophobic amino acids (382 mg/g protein) compared to those of cowpea (329 mg/g protein). Protein hydrolysates of both beans from alcalase hydrolysis have higher ACE-1 inhibitory activity rather than those from flavourzyme. Protein hydrolysate from Vigna spp bean protein hydrolysis by alcalase, contained small molecular weight peptides (3.9-4.63 kDa) and high ACE-1 inhibition ability (80-93 %), and therefore suggested as antihypertensive nutraceuticals. Highest solubility of protein hydrolysates resulted from alcalase hydrolysis of both beans were observed at pH 8, while those resulted from flavorzyme hydrolysis were at pH 7, respectively.
The adsorption to and hydrolysis of 1,3-didecanoyl glycerol monolayers by pancreatic lipase. Effects of substrate packing density.
