Antioxidant Coagulase-Negative Staphylococcus Strains: In Vitro Screening and Effects on the Oxidative Stability and Quality of Harbin Dry Sausages

This study aimed to investigate the antioxidant capacity of five coagulase-negative staphylococci (CNS) strains and their effects on the oxidative stability and quality characteristics of Harbin dry sausages. Among the five CNS strains, three with relatively high H2O2 tolerance, namely Staphylococcus equorum HRB2, Staphylococcus xylosus HRB1, and Staphylococcus epidermidis HS1, whose H2O2 concentrations resulting in 50% survival were 50, 80, and 90 mmol/L, respectively, were selected for in vitro antioxidant assessment. Among them, S. xylosus HRB1 exhibited the highest reducing power, hydroxyl radical scavenging activity, catalase activity, and glutathione peroxidase activity. Furthermore, inoculation with S. xylosus HRB1 and S. epidermidis HS1 significantly inhibited lipid and protein oxidation in dry sausages (p < 0.05). Notably, inoculation with S. xylosus HRB1 reduced thiobarbituric acid reactive substances value by 22.73% and carbonyl content by 18.87% compared with the non-inoculated control. Moreover, inoculation with S. xylosus HRB1 significantly reduced undesirable aldehydes and acids (p < 0.05). Sensory evaluation revealed that dry sausages inoculated with S. xylosus HRB1 received the highest scores for color and aroma, and the lowest scores for off-odor. In conclusion, S. xylosus HRB1, as a promising antioxidant starter culture, could effectively inhibit oxidation and simultaneously enhance the quality characteristics of Harbin dry sausages.