Fermentation characteristics of Lactobacillus brevis and Lactobacillus plantarum

Abstract:

[Background] The current studies about the fermentation of Chinese sauerkraut mainly focus on Lactobacillus plantarum, while there are few reports on L. brevis in Chinese sauerkraut. [Objective] To explore the fermentation performance of L. brevis and develop the starter of Chinese sauerkraut fermentation, we designed two strain combinations (two strains of L. brevis and one strain of L. plantarum) for fermentation to explore the effect of L. brevis on the quality of Chinese sauerkraut. [Methods] The growth, acid production capacity, acid resistance, and nitrite degradation capacity of single strains of L. brevis and L. plantarum were measured. During days 1-7 of the fermentation with the two strain combinations, the acidity, viable cell count, nitrite content, and texture changes of Chinese sauerkraut were measured. [Results] L. brevis Lb-5-3 had slower growth and acid production rate, weaker acid tolerance, and stronger nitrite degradation ability than L. brevis Lb-9-2. After the two strains were respectively combined with L. plantarum Lp-9-1, their acid production significantly increased and the pH value was the lowest (about 3.10) on day 3. The addition of Lp-9-1 delayed the growth of Lactobacillus in Chinese sauerkraut and the viable cell count peaked on day 5. The nitrite content of the samples inoculated with the combined strains varied gently from day 1 to day 7 and showed no significant difference between the two combinations in the first 5 days. The inoculation of Lactobacillus decreased the hardness and elasticity of Chinese sauerkraut, and the hardness was the highest on day 3 of fermentation with the combination of Lb-5-3/Lp-9-1. The sensory score of the Chinese sauerkraut fermented with Lb-5-3/Lp-9-1 was the highest on day 3 of fermentation. [Conclusion] Therefore, the combination of L. brevis and L. plantarum could produce Chinese sauerkraut with low nitrite content and good comprehensive properties within 3 days. L. brevis in the strain combination did not affect the acid production or nitrite degradation, while it affected the hardness and sensory properties of Chinese sauerkraut. This study is of great significance to the performance evaluation of new Lactobacillus strains and the development of starter for the production of Chinese sauerkraut.

Key words:Chinese sauerkraut;fermentation characteristics;nitrite degradation;Lactobacillus plantarum; Lactobacillus brevis