This study investigated and compared the differences in gastrointestinal digestion among fresh pork, Chinese sausage, and Chinese sausage inoculated with Staphylococcus (S.) carnosus RT6. The results indicated that fermentation treatment improves gastric digestibility by inducing protein denaturation, transforming β-sheets into random coils and β-turns. The sausages inoculated with S. carnosus exhibited the best protein digestion characteristics, with the highest combined gastric/intestinal digestibility (77.38%). During in vitro gastrointestinal digestion, sausage inoculated with S. carnosus RT6 released more peptides (517) than traditional Chinese sausages (304) and fresh pork (134). The S. carnosus RT6 inoculate also yielded a higher proportion of peptides with molecular weights <1000 Da (36.21%) and more unique peptides. Furthermore, the digested peptides from the S. carnosus RT6 treatment were more widely distributed across the 3D structure of actin than those from the other treatments. The digested products of sausage inoculated with S. carnosus RT6 demonstrated superior radical scavenging activity, with DPPH, hydroxyl (·OH), and ABTS radical scavenging rates reaching 71.3%, 83.2%, and 80.5% respectively, and enhanced overall antioxidant capabilities. This study highlights the potential application of S. carnosus RT6 as a starter culture to enhance the nutritional quality of fermented sausage.

In this work, the effect of sodium bicarbonate on the processing and cold storage properties of poached beef slices was studied. Beef slices were cured with sodium bicarbonate (0.2%–0.8%). After being cooked, the slices were refrigerated at 4 ℃ for up to 8 days. The changes in cooking yield, color, pH, shear force, moisture content and thiobarbituric acid reactive substances value during processing and refrigeration were measured. The results showed that sodium bicarbonate significantly increased (P < 0.05) the yield, pH and moisture content of poached beef slices, and significantly decreased (P < 0.05) the shear force and a* value. During refrigeration, the moisture content and L* and a* values of all samples decreased, and the b* values increased. Sodium bicarbonate could inhibit fat oxidation, and this effect was more pronounced with increasing concentration of sodium bicarbonate. In addition, sodium bicarbonate significantly inhibited the decrease in the a* value of poached beef slices, and the a* value of the samples supplemented with sodium bicarbonate was higher than that of the control group. Overall, sodium bicarbonate can improve the water retention, tenderness and oxidation stability of poached beef slices.