Sichuan paocai fermented by mixed-starter culture of lactic acid bacteria

Abstract

To satisfy the demand of industrial production, selecting strains suitable for fermentation initiation is necessary. In this study, the effects of mixed-starter culture including Leuconostoc, Lactobacillus, and Weissella on the quality of Sichuan pickle were discussed. Results showed that mixed-starter culture can accelerate fermentation and had the highest efficiency for nitrite degradation, that is, the maximum nitrite concentration was 8.97 g/kg on day 1 and decreased to 1.88 mg/kg after 3 days. The mixed-starter culture improved the sensory properties of pickles, which easily produced acids but had reduced amounts of total acids. The pickle products fermented by the mixed-starter culture contained increased lactic acid (17.52 g/kg), mannitol (0.62%), umami (35.85), and sweet (11.36) amino acids on day 4. The strains Weissella paramesenteroides C2-2 and Lactobacillus brevis ZP11-2 grew well in the mixed-starter culture fermentation.

Keywords: Brassica juncea var. tumida Tsen; Lactobacillus; Leuconostoc; Sichuan paocai; Weissella; mixed‐starter culture.

FIGURE 1

pH and titratable acidity of brine solution during fermentation. (a) pH of brine solution during fermentation. (b) Titratable acidity of the brine solution during fermentation (g/kg). The treatment group was inoculated with mixed‐starter cultures at 1:1:1 ratio of L1–L2–W. The spontaneous fermentation with no starter was as control. The brine samples were collected on days 0, 1, 2, 3, 4, 7, and 10 after vegetable submersion

FIGURE 2

Nitrite levels of the brine solution during fermentation (mg/kg) The treatment group was inoculated with mixed‐starter cultures at 1:1:1 ratio of L1–L2–W. The spontaneous fermentation with no starter was as control. The brine samples were collected on days 0, 1, 2, 3, 4, 7, and 10 after vegetable submersion

FIGURE 3

Microbial analysis in fermented paocai pickle brine. (a) Lactic acid bacteria population in fermented paocai pickle (lg(CFU/ml)). (b) Total aerobe population in fermented paocai pickle (lg(CFU/ml))

FIGURE 4

qPCR analysis of three LABs in paocai brine. Asterisks indicate significant differences (*Pb0.05 and **Pb0.01) between treatment and control. A letter indicates differences compared with that on 0 day in the same treatment. Error bars represent the mean ± SD of three independent PCR amplifications and quantifications