Screening, Mutagenesis of Nitrite‐Degrading Lactobacilli in Chinese Traditional Fermented Sauerkraut and its Application in the Production of Sauerkraut

Abstract

AbstractSauerkraut is a Chinese traditional fermented vegetable product. However, excessive nitrite in sauerkraut may cause food safety problems. This study screened three highly‐efficient nitrite‐degrading lactobacilli, namely, B1, C1 and D2, with over 75% degradation rate. According to the morphology, physiological and biochemical characteristics, as well as the 16S rDNA analysis, we found that B1 belonged to Lactobacillus pentosus, whereas C1 and D2 belonged to Lactobacillus plantarum. After ultraviolet (UV)‐nitrosoguanidine compound mutation, the degradation rates of the three lactobacilli to nitrite improved by 5.8, 8.0 and 12.7%, respectively. After the acclimation of sauerkraut juice with 80% concentration, single lactobacillus and mixed lactobacilli were applied in the sauerkraut product. The results indicated that the degradation effects of mixed strains on nitrite were better than that of single one. Compared with the control group (0–36.6 mg/kg), the mixed strains inoculated in the early fermentation period can significantly decrease the nitrite residue in sauerkraut (0–20.8 mg/kg) and the fermentation period can be shortened from 30 to 20 days. The sauerkraut produced showed good quality and flavor. Therefore, this study has significant application value for industrial production of sauerkraut.Practical ApplicationsNitrite formed in traditional fermented sauerkraut is an unsolved safety problem. This study screened three highly‐efficient nitrite‐degrading lactobacilli strains. After ultraviolet (UV)‐nitrosoguanidine compound mutation, the degradation rates of the three lactobacilli to nitrite were over 81.5%. Compared with the control group (36.6 mg/kg), the mixed strains inoculated in the early fermentation period could significantly decrease the nitrite residue in sauerkraut (20.8 mg/kg) and the fermentation period could be shortened from 30 to 20 days. Therefore, this study has significant application value for the industrial production of sauerkraut.