摘要
选用从西北地区泡菜中分离出的6株乳酸菌(植物乳杆菌、乳杆菌、副干酪乳杆菌、发酵乳杆菌、戊糖乳杆菌、短乳杆菌)进行降解亚硝盐能力测试,筛选得到具有较强亚硝酸盐降解力的4株供试菌。然后选用10种蔬菜对供试菌进行增菌培养基的初筛,在此基础上扩大培养复筛。并对供试菌离心浓缩后,按照等比例与保护剂混合进行菌体悬浮,再喷雾干燥制备菌粉。按照不同的接菌量进行泡菜发酵实验,最后验证了泡菜发酵剂的保存时间。结果表明:亚硝酸盐的降解率依次为87%,93%,88%,88%,83.2%,85.5%,同时选取黄瓜汁作为4株供试菌的增菌培养基时,活菌数都达到1011 cfu/mL以上;L1,L3和L4的最佳离心条件为4℃下离心转速为6000r/min,离心10min;L2的最佳离心条件为4℃下离心转速为6000r/min,离心20min,泡菜发酵过程中接种量为4%时最佳,发酵120h亚硝酸盐含量降为0mg/kg;不同的保存条件对发酵剂中活菌数下降的速度影响差异很大,随着保存时间的延长,发酵剂中活菌数呈指数下降趋势,与室温相比较,4℃条件下活菌数下降比较慢。
Six strains of lactic acid bacteria （Lactobacillus harbinensis, Lactobacillus plantarum, Lactobacillus brevis , Lactobacillus f ermentum , Lactobacillus pentose , Lactobacillus paracasei ） isolated from the northwestern pickles are tested with their capacity of degradation nitrate in this paper, and four strains of bacteria are chosen. Then ten kinds of vegetables are selected for the preliminary screening of enrichment medium, based on which, expand training is performed. And after the centrifuge enrichment, the tested bacteria of same proportion will mix with protective agent, and preparation of spray-dried powder. Pickle fermentation experiments will be performed according to different amounts of inoculum, finally, the save time of pickle starter is validated. The result shows that degradation rates of nitrite are 87%, 93%, 88%, 88%, 83.2%, 85.5%, at the same time, the viable count is up to 1011 cfu/mL, when the cucumber juice is selected as enrichment medium the optimal centrifugal speed of L1, 1.3 and LA is 6000 r/min, 4 ℃, 10 rain; and 6000 r/min, 4 ℃, 20 rain is the best centrifugal condition for L2. The best inoculum is 4% during inoculated fermentation and the nitrite content reduced to 0 mg/kg after 120 h; decline rate of living bacteria number is affected greatly by the preservation condition. As the time sustains, the number of living bacteria in the starter declines exponentially, and compared with the room temperature ,the bacterial count declines more slowly in the temperature of 4 ℃.
出处
《中国调味品》
CAS
北大核心
2016年第1期35-41,共7页
China Condiment
基金
陕西省科技统筹创新工程计划项目(2011KTCQ03-08)
关键词
亚硝酸盐
泡菜
乳酸菌
发酵剂
nitrite
pickle
lactic acid bacteria
starter
