Antioxidant Activity of Peptides Obtained from Wheat and Cottonseed Proteins

BOBOEV, A., A. HASANOV, L. YOTOVA and H. HASANOV, 2012. Antioxidant activity of peptides obtained from wheat and cottonseed proteins. Bulg. J. Agric. Sci., 18: 103-111 Enzymatic hydrolysis of various wheat proteins and cottonseed with acid (Prolive PAC 30L “EnzymeBioProduct” Ltd, Russia) and neutral proteases (Neutrase, ‘’Novozymes’’, Denmark) was studied. The antioxidant properties of the produced peptides depended on the properties of the proteins and enzymes used. It was shown that when using acid protease peptides, derived from wheat albumin possess 10-12 times higher reducing power than peptides derived with neutral protease. When using cottonseed albumin, a different relationship was established. Reducing power of peptides, produced with neutral protease was 2-3 times higher than peptides processed using acid proteases. When hydrolyzing cottonseed globulin, the reducing power of the resulting peptides is higher, when acid protease is used. In a model system, the highest inhibition rate of oxidation of (+)-catechin is observed when peptides derived from cottonseed and wheat proteins with neutral proteases were used. In all cases, peptides derived with acid protease reduce the rate of oxidation of (+)-catechin to a smaller degree. Apart from having antioxidant activity, the peptides can also affect the activity of antioxidant enzymes. Activating effect is observed at low degrees of hydrolysis of albumin and it depends on the type of the enzyme and the substrate protein.