Improvement of fermented Chinese cabbage characteristics by selected starter cultures.

UNLABELLED: Traditional fermented vegetables have inconsistent quality and high nitrite content, whereas a commercial starter culture could overcome these problems. A total of 34 lactic acid bacteria strains were screened from 2 homemade naturally fermented Chinese cabbages. Fermented characters of single starter or mixed cultures were examined, including acidification, growth rate, and nitrite depletion ability in the fermented culture. As a result, the combined starter culture (Lactobacillus delbrueckii IWQ and Lactobacillus paracasei J21) was selected. The fermented Chinese cabbage resulted from this mixed starter culture had higher sugar content residue (30.5 mg/mL for mixed culture and 22 mg/mL for control). And the titratable acid of the cabbage fermented by the mixed starter was 110°T, which was twice higher than that of control sample. The selected starter culture also had a better texture and sensory qualities than that the starter cultures from a local fermented Chinese cabbage plant, especially for its significantly lower nitrite content (3.00 mg/kg for mixed culture and 4.49 mg/kg for control). The findings of this study form a database for further studies on the development of starter cultures for fermented cabbage production and could replaced the local plant starter culture. PRACTICAL APPLICATION: LABs were screened from traditional fermented food. The fermented characteristics of selected LABs were better than that of starter cultures from a local Chinese cabbage plant. Selected LAB can decrease nitrite content in fermented cabbage. The Chinese cabbage fermented by the selected LAB had the good flavor and texture.