Peptides from cowpea present antioxidant activity, inhibit cholesterol synthesis and its solubilisation into micelles

• Published in: Food chemistry Vol. 168; pp. 288 - 293
• Main Authors: Marques, Marcelo Rodrigues, Soares Freitas, Rosana Aparecida Manólio, Corrêa Carlos, Amanda Caroline, Siguemoto, Érica Sayuri, Fontanari, Gustavo Guadagnucci, Arêas, José Alfredo Gomes
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-02-2015; Elsevier
• Subjects: Antioxidants - pharmacology; Biological and medical sciences; Cholesterol; Cholesterol - biosynthesis; Cowpea bean; Fabaceae - chemistry; Food toxicology; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors - pharmacology; Medical sciences; Micelles; Peptide fraction; Peptides - chemistry; Peptides - pharmacology; Solubility; Thermal processing; Toxicology; Peptide fraction; Thermal processing; Cowpea bean; Cholesterol; Vegetables; Peptides; Micelle; Lipids; Cowpea; Biosynthesis; Antioxidant; Solubilization; Bean; Food
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.07.049

•Cooking and enzymatic digestion of cowpea release peptides, which are capable of inhibiting HMGCR.•Thermal processing improves their ability to decrease cholesterol micellar solubilisation.•Peptides smaller than three kDa presented better antioxidant activity.•Thermal processing decreased this antioxidant capacity.•Inhibition routes explain effect of cowpea protein on lipid metabolism.
In previous studies, it was reported that the protein isolated from the cowpea interferes favourably in lipid metabolism, and reduces cholesterol synthesis. The present study investigated the role of cowpea peptide fractions in the micellar solubilisation of cholesterol, in the 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) activity, and in the in vitro antioxidant capacity, considering the effects of thermal processing. The protein was isolated from the raw and cooked beans and digested to simulate human digestion. The peptides from the protein isolate of raw bean with molecular mass lower than 3kDa reduced 89% of the HMGCR enzymatic reaction velocity. The cooked cowpeas were more effective in inhibiting the micellar solubility of cholesterol than the raw ones but not the antioxidant activity. This is the first report that cowpea peptides inhibit cholesterol homeostasis in vitro in two distinct routes, and act as an antioxidant.