Effect of Different Inoculum Levels of Lactobacillus plantarum on Quality Characteristics and Flavor Profile of Low-Sodium Dry Sausage

The effect of different inoculum levels of Lactobacillus plantarum (10⁵, 10⁶ and 10⁷ CFU/g) on the quality characteristics and flavor profile of low-sodium dry sausage were explored in this study. The uninoculated sausage with 1.75% NaCl was regarded as a control. The pH, moisture content, water activity, shear force, lactic acid bacteria (LAB) count and Enterobacteria count of the four samples were measured on days 0, 3, 6 and 9 of fermentation and the flavor profiles were analyzed on the 9^th day by electronic nose (EN) and gas chromatography-mass spectrometry (GC-MS). The results showed that the moisture content and water activity of all treatments decreased gradually as the fermentation progressed; at the end of fermentation (day 9), the moisture contents and water activity of the LP6 and LP7 treatments were higher than those of the other treatments and the Enterobacteriaceae count of the LP7 treatment was the lowest among all treatments, while there was no significant difference in shear force among all treatments (P > 0.05). The pH of all treatments decreased gradually (except for day 0 of fermentation) with an increase in the inoculum level, and the LAB count increased gradually (except for day 6 of fermentation). Inoculation with L. plantarum increased the contents of acids and esters. The volatile compound contents of low-sodium dry sausages with different inoculum levels of L. plantarum were significantly different. Finally, sensory evaluation indicated that the overall acceptability of low-sodium dry sausage with an inoculum level of 10⁶ CFU/g was the highest, and its saltiness and sourness were moderate.