Abstract: In this study, we aimed to investigated the effect of mixed cultures on improving the physiochemical properties, flavor and antioxidant activity of peptides of fermented mutton sausage. The physicochemical indexes such as pH, color and texture, as well as the types and contents of free amino acids and volatile flavor substances in fermented mutton sausage prepared with mixed culture of Lactobacillus plantarum CD101 and Staphylococcus simulans NJ201 and naturally fermented sausage as a control were measured, and the scavenging ability of peptides extracted from the sausages against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationic radicals and hydroxyl radicals were tested. The results showed that the mixed culture was able to rapidly reduce the pH of fermented mutton sausage during fermentation, improve its safety, enhance its brightness, color, hardness and chewiness, thereby improving its quality. Moreover, the mixed culture increased the total amount of free amino acids, the types and contents of volatile flavor substances and consequently enhanced the flavor of fermented mutton sausage, as well as significantly increased the radical scavenging capacity of peptides from fermented mutton sausage. In conclusion, inoculated fermentation could significantly improve physicochemical properties, flavor and antioxidant capacity of peptides from fermented mutton sausage. This study can provide a theoretical basis for the industrial production of fermented meat products.

Key words: inoculated fermentation; fermented mutton sausage; physicochemical properties; volatile flavor substances; antioxidant capacity