Comparison of the quality of suansun product between starter inoculation and natural fermentation

Suansun (fermented bamboo shoots) was prepared by natural fermentation (NF) and inoculation fermentation (IF) with a starter culture containing Lactococcus lactis, Leuconostoc citreum, and Lactiplantibacillus plantarum in this study, to evaluate the effects of inoculation mixed starter culture on physicochemical, flavor and sensory characteristics of suansun. The results showed that IF suansun acidified faster and to a greater extent than NF. Besides, the accelerated acidification process significantly decreased the nitrite content, shortened the fermentation time and improved the food safety of the final suansun product in IF. At the end of fermentation, the lactic acid concentration was significantly higher in IF (6.17 ± 0.25 g/L) than in NF (3.83 ± 0.28 g/L). Twenty-seven volatile compounds were identified as the characteristic flavor compounds in suansun and the relative content of nonanal, hexanal, 1-octen-3-ol and 3-octanone (ROAV >1) was higher in IF than in NF at the late stage of fermentation. In addition, 132 non-volatile compounds were identified as significant differential metabolites, which were mainly small peptides and fatty acids in both NF and IF. Sensory evaluation found that the aroma, taste, texture and overall quality scores of IF suansun were all superior to those of NF suansun. The above results demonstrated that the use of mixed starter cultures of Lac. lactis, Leu. citreum, and L. plantarum contributed to improving the quality of suansun product, and might provide a feasible approach for standardized production of suansun in the future.