一株乳酸乳球菌的分离鉴定及其发酵豆汁工艺优化
Isolation and identification of Lactococcus lactis and process optimization in fermented beverage of mung bean
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摘要: 本研究从自然发酵北京豆汁中筛选到一株既可以加速豆汁与淀粉分离又具有优良豆汁发酵性能的乳酸乳球菌乳酸亚种,将其命名为Lactococcus lactis subsp.lactis LLY003。然后以绿豆淀粉的副产物——淀粉上清液为原料,将Lactococcus lactis subsp.lactis LLY003应用于豆汁发酵,通过单因素和正交实验,确定了发酵豆汁的最佳发酵工艺:在发酵时间为6 h,温度为39℃,6%蔗糖添加量和8%接种量的条件发酵,豆汁的感官评分达到94分,乳酸菌活菌数可以达到3.22×1011CFU/m L。通过保质期实验,确定发酵豆汁在4℃冷藏条件下,保质期至少可达20 d,在保质期内每毫升发酵豆汁的乳酸菌活菌数在一千亿以上。Abstract: A strain of Lactococcus lactis subsp.lactis with accelerating the separation of starch and good fermentation properties was isolated from Beijing Douzhi by natural fermentation. This strain was named Lactococcus lactis subsp.lactis LLY003 and applied to fermentation beverage and the supernatant of mung bean starch as substrate. Then the single factor experiment and orthogonal experiment were designed for optimizing the technology parameters. The optimal fermentation condition was inoculated amount 8% at 39 ℃ for 6 hours with 6% aucrose, under these conditions, the values of sensory reached 94 scores and the viable cells reached 3.22 × 1011CFU/m L.The storage shelf life could reach up to 20 days at 4 ℃ and the viable cells above one hundred billion.
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