Casein peptides with inhibitory activity on lipid oxidation in beef homogenates and mechanically deboned poultry meat

Bioactive peptides obtained by enzymatic hydrolysis of casein may have antioxidant activity. In this work, casein peptides were obtained using the proteolytic enzymes Alcalase and Flavourzyme. Casein was hydrolyzed for 4 h at 50 degrees C and pH 8, and the resulting peptides were analyzed. The enzymatic hydrolysis with Flavourzyme resulted in higher concentration of soluble protein and free amino acids, and produced peptides with lower molecular mass than those obtained with Alcalase, as observed by gel permeation chromatography and polyacrylamide gel electrophoresis. Casein peptides obtained with Flavourzyme also exhibited greater antioxidant capacity using the ABTS radical method. Casein peptides (20 mg ml(-1)) effectively inhibited lipid peroxidation in ground beef homogenates and mechanically deboned poultry meat. Casein peptides may be useful in meat processing as another naturally occurring antioxidant, helping to prevent off-flavor formation in meat products and increasing shelf life. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.