短乳杆菌与植物乳杆菌的发酵特性

【背景】目前对于酸菜发酵的研究主要关注点是植物乳杆菌(Lactobacillus plantarum)，有关短乳杆菌(Lactobacillus brevis)在酸菜方面的研究报道很少。【目的】为了挖掘短乳杆菌的发酵性能并开发酸菜发酵剂，将2株短乳杆菌分别与1株植物乳杆菌进行组合并发酵酸菜，分析短乳杆菌对酸菜发酵品质的影响。【方法】分别测定短乳杆菌与植物乳杆菌的单菌株生长产酸性能、耐酸性及亚硝酸盐降解力，并将两菌种组合后发酵酸菜，分析1-7d内酸度、乳酸菌活菌数、亚硝酸盐含量及酸菜质构特性的变化趋势。【结果】相较于短乳杆菌Lb-9-2，短乳杆菌Lb-5-3的生长和产酸速率较慢、酸耐受力较弱，但其亚硝酸盐降解力较强。两株短乳杆菌分别与植物乳杆菌Lp-9-1组合后产酸力显著增强，并在3 d时达到最低pH值(约3.10)；植物乳杆菌Lp-9-1的添加使酸菜中总体乳酸菌生长延迟，在5 d时达到最高活菌数；组合菌种的样品中亚硝酸盐含量在1-7 d内变化较为平缓，前5天内两个组合之间差异不显著；接种乳酸菌会降低酸菜硬度和弹性，发酵3d时Lb-5-3/Lp-9-1组合的硬度最大，感官评价得分最高。【...

Fermentation characteristics of Lactobacillus brevis and Lactobacillus plantarum

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.