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比较益生菌干酪乳杆菌Zhang(L.casei Zhang)与商业化益生菌嗜酸乳杆菌NCFM(NCFM)、鼠李糖乳杆菌GG(LGG)、干酪乳杆菌Shirota(LcS)、动物双歧杆菌Bb12(Bb12)对人工胃肠液的耐受性及发酵特性。将各菌置于人工消化液及含3.0g/L牛胆盐的MRS培养基中,37℃培养,分别于3h和8h时测定人工胃液和肠液中各菌株的存活率,同时每小时测定MRS培养基的浊度,以延迟时间评价各菌株对胆盐的耐受性。对由各菌株制得的发酵乳在发酵及贮藏期间酸度与活菌数的变化进行了测定,结果表明,在pH2.5的人工胃液消化3h后,干酪乳杆菌Zhang存活率低于NCFM(p<0.05),高于其它3株对照菌(p<0.05);在pH3.0和pH4.0的人工胃液消化3h后,干酪乳杆菌Zhang的存活率与4株对照菌无显著差异(p>0.05);在pH8.0的人工肠液消化8h后,干酪乳杆菌Zhang的存活率高于Bb12(p<0.05),低于NCFM(p<0.05),与其它2株对照菌无差异(p>0.05)。干酪乳杆菌Zhang对3.0g/L牛胆盐的耐受性与LcS差异不显著(p>0.05),而高于其它3株对照菌(p<0.05)。脱脂乳37℃发酵24h后,接种干酪乳杆菌Zhang的样品的酸度低于4株对照菌。4℃贮藏28d内,各益生菌在发酵乳中继续生长,其中干酪乳杆菌Zhang发酵乳的pH值变化(降低0.55)显著高于4株对照菌(p<0.05);贮藏28d后干酪乳杆菌Zhang活菌数为1.0×109cfu/g,显著高于4株对照菌(p<0.05),说明干酪乳杆菌Zhang具有良好的胃肠转运耐受性和极佳的贮藏稳定性。
Comparison of Probiotic Lactobacillus casei Zhang (L.casei Zhang) with Commercial Probiotic Lactobacillus acidophilus NCFM (NCFM), Lactobacillus rhamnosus GG (LGG), Lactobacillus casei Shirota (LcS), Bifidobacterium animalis Bb12 (Bb12) on artificial gastrointestinal fluid tolerance and fermentation characteristics. The bacteria were placed in artificial digestive juice and MRS medium containing 3.0g / L bovine bile salts, cultured at 37 ℃, respectively, at 3h and 8h determination of the artificial gastric juice and intestinal fluid survival of each strain, while the hourly determination of MRS The turbidity of the medium was evaluated by delay time as to the bile salt tolerance of each strain. The changes of acidity and viable count of fermented milk produced by each strain during fermentation and storage were measured. The results showed that the survival rate of Lactobacillus casei was lower than that of NCFM (p <0.05), higher than the other three control strains (p <0.05). After the artificial gastric juice was digested with pH3.0 and pH4.0 for 3h, the survival rate of L. casei Zhang was no significant difference with that of the four control strains (p> 0.05). The survival rate of L. casei Zhang was higher than that of Bb12 (p <0.05) and lower than that of NCFM (p <0.05) after digested with artificial intestinal juice at pH8.0 for 8h, but no difference with other two control strains (p> 0.05). Lactobacillus casei Zhang was not significantly different from LcS in 3.0g / L bovine bile salt (p> 0.05), but higher than the other three control strains (p <0.05). After fermented at 37 ℃ for 24 h, the acidity of samples inoculated with L. casei Zhang was lower than that of 4 control strains. During the 28 days of storage at 4 ℃, the probiotics continued to grow in the fermented milk. The pH value of the fermented milk (by 0.55) was significantly higher than that of the four strains (p <0.05) The viable count of Zhang was 1.0 × 109cfu / g, which was significantly higher than that of 4 control strains (p <0.05), indicating that L. casei Zhang had good gastrointestinal transit tolerance and excellent storage stability.