Structural characteristics of peptides extracted from Cantonese sausage during drying and their antioxidant activities

Two peptide fractions (P1 and P2) were isolated from Cantonese sausages at different drying periods by ultrafiltration. PI possessed a stronger 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in the first 18 h of drying and a weaker activity during the rest period, comparing with P2. The analysis of amino acid composition indicated that histidine was the major amino acid in both peptide fractions, which content was changed during the process. In addition, Glu, Gly, Arg were important constituent amino acids in both peptide fractions. A significant (P<0.05) decrease of >10 kDa peptide fraction and increases of 2-3 and <2 kDa peptide fractions were detected when comparing with peptides at 0 h. However, no significant difference was found for all the peptide fractions at different drying periods, except for 2-3 kDa peptides. A significant (P<0.05) correlationship was found between lipid oxidation and antioxidant activities. Industrial relevance: Cantonese sausage has gained much popularity and acceptance in China and many other countries. In this work, two peptide fractions were isolated from Cantonese sausage. A good antioxidant activity was observed for each peptide fraction. Endogenous peptides resulting from proteolysis offer a promising approach to improve lipid stability for meat industry. It is helpful to retard lipid oxidation in order to improve its quality. (C) 2009 Elsevier Ltd. All rights reserved.