title: Release of angiotensin I converting enzyme (ACE) inhibitory activity during in vitro gastrointestinal digestion: from batch experiment to semicontinuous model.
abstract: Gastrointestinal digestion is of major importance in the bioavailability of angiotensin I converting enzyme (ACE) inhibitory peptides, bioactive peptides with possible antihypertensive effects. In this study, the conditions of in vitro gastrointestinal digestion leading to the formation and degradation of ACE inhibitory peptides were investigated for pea and whey protein. In batch experiments, the digestion simulating the physiological conditions sufficed to achieve the highest ACE inhibitory activity, with IC(50) values of 0.076 mg/mL for pea and 0.048 mg/mL for whey protein. The degree of proteolysis did not correlate with the ACE inhibitory activity and was always higher for pea than whey. In a semicontinuous model of gastrointestinal digestion, response surface methodology studied the influence of temperature and incubation time in both the stomach and small intestine phases on the ACE inhibitory activity and degree of proteolysis. For pea protein, a linear model for the degree of proteolysis and a quadratic model for the ACE inhibitory activity could be constituted. Within the model, a maximal degree of proteolysis was observed at the highest temperature and the longest incubation time in the small intestine phase, while maximal ACE inhibitory activity was obtained at the longest incubation times in the stomach and small intestine phase. These results show that ACE inhibitory activity of pea and whey hydrolysates can be controlled by the conditions of in vitro gastrointestinal digestion.
authors.affiliation: Laboratory of Microbial Ecology and Technology, Faculty of Agricultural and Applied Biological Sciences, Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Vermeirssen
authors.forename: John
authors.initials: J
authors.lastname: Van Camp
authors.forename: Liesbet
authors.initials: L
authors.lastname: Devos
authors.forename: Willy
authors.initials: W
authors.lastname: Verstraete
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000378:metabolism*; D004063:Digestion; D004064:Digestive System / Q000201:enzymology / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism; D006868:Hydrolysis; D066298:In Vitro Techniques; D008894:Milk Proteins / Q000378:metabolism; D018532:Pisum sativum / Q000737:chemistry; D010455:Peptides / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D000067816:Whey Proteins
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D008894:Milk Proteins; D010455:Peptides; D010940:Plant Proteins; D000067816:Whey Proteins; D010450:Endopeptidases