植物乳杆菌LPb1耐受性及发酵乳制备条件的优化

Gastrointestinal Tolerance of Lactobacillus plantarum LPb1 and Optimization of Fermentation for Yogurt Production

模拟人体消化道环境,即在人工胃液、肠液的环境下对植物乳杆菌LPb1的耐受性进行研究,结果表明:在37℃条件下,用人工胃液处理3h,收集的菌体再转入人工肠液处理3h,最后测得菌株存活率仍达88.6%。LPb1与一株嗜热链球菌混合发酵脱脂乳,与单菌发酵相比,混合菌产酸效果较好,发酵乳制品具有良好的持水性能,且发酵完成后,4℃冰箱贮存后酸化程度缓慢。通过单因素和响应面分析,混合发酵最佳发酵条件为:接种量4.45%、发酵时间8.53h、发酵温度40.40℃。

The tolerance of Lactobacillus plantarum LPb1 in stimulated human digestive environment such as artificial gastric and intestinal fluid was tested.Lactobacillus plantarum LPb1 was first trrsyrf with artificial gastric juice for 3 h,then with artificial intestinal juice for another 3 h at 37 ℃,the survival rate of Lactobacillus plantarum LPb1 cells was 88.6%.LPb1 mixed with a strain of Streptococcus thermophilus was inoculated into skim milk to produce yogurt.The results showed the combination starter produced acid well and the final products had good water retention property,meanwhile the yogurt was weak in post-acidifying activity at the storage temperature（4 ℃）.Taking sensory evaluation as indicators,the optimum fermentation conditions were inoculums size of 4.45% of mixed culture,fermentation temperature 40.40 ℃,and fermentation time 8.53 h.