【作者】 王丽；

【导师】 双全；

【作者基本信息】 内蒙古农业大学 ， 食品工程， 2015， 硕士

【摘要】 本文以从内蒙古传统发酵食品中分离的乳酸菌为对象,选用LB培养基进行初筛的基础上,在红豆乳中以产酸能力和蛋白质分解能力进行复筛,再对筛选出的菌株进行驯化后应用于无糖发酵红豆乳,通过单因素试验和正交试验研究其最佳工艺条件。结果表明：从50株供试乳酸菌经初筛获得了3株生长状况较好的菌,分别为菌株S2-4、Sc8-1和NM-6。在4%的红豆乳中进行复筛获得了1株较好的菌NM-6,其在37℃培养48h时的总酸度和游离氨基氮含量分别为0.27%和1.215mmol/L。再对菌株NM-6进行驯化后,其总酸度和游离氨基氮含量分别达到0.43%和1.523mmol/L,比驯化前分别提高了59.3%和25.3%。经单因素试验和正交试验得到发酵红豆乳的最佳工艺条件为：红豆乳浓度为5%、赤藓糖醇添加量为1.5%、菌株NM-6的接种量为4%、发酵时间16h、发酵温度37℃。此最佳工艺条件下,酸乳的游离氨基氮含量可达到1.524mmol/L。通过比较可得试验中添加0.10%的复合稳定剂(果胶：CMC=1：1)时产品的离心率最小,稳定效果最佳。对菌株NM-6进行16SrDNA测序,得到的基因序列全长共1461bp,经分析将其鉴定为乳酸片球菌(Pediococcus acidilactici)。更多还原

【Abstract】 The growth ability of lactic acid bacteria isolated from the traditional fermented food in Inner Mongolia were screened in the sugar-free LB medium, and its capability of acid producing and protein decomposition were measured in the red bean milk. Then the protein decomposition capability of selected strain was tamed gradually, and the optimum process conditions of fermented red bean milk were determined through single factor experiment and orthogonal experiment. The results showed that:Three strains (S2-4, Sc8-1 and NM-6) were screened out with good growth ability from 50 lactic acid bacteria strains, and one of the best strain NM-6 was selected by measuring protein decomposition capability in the 4% of red bean milk, and its total acidity and the free amino nitrogen content at 37℃ for 48h were 0.27% and 1.215mmol/L, respectively. After taming, the total acidity and the free amino nitrogen content of strain NM-6 could achieve to 0.43% and 1.523mmol/L, and would be improved 59.3% and 25.3% than before.Through single factor experiment and orthogonal experiment got the optimum process conditions of fermented red bean milk:the concentration of red bean milk was 5%,the eythritol addiction was 1.5%, the inoculum of strain NM-6 was 4%, the fermentation time was 16h,the fermentation temperature was 37℃.In the optimum technological conditions the free amino nitrogen content of sour milk could achieve to 1.524mmol/L.At last the best complex stabilizer addiction (pectin:CMC=1:1) was 0.10% when the eccentricity of product was the least and the stable effect was the best.To analysis the 16SrDNA sequence of strain NM-6, the total length of gene sequences were 1461bp, at last the strain NM-6 was identified as Pediococcus acidilactici.更多还原