大蒜果聚糖对乳杆菌的体外增殖作用研究

Study on evaluation of prebiotic effects of three garlic fructans in vitro

通过体外实验,研究了三种不同聚合度的大蒜果聚糖Garlic Fructans(GF1、GF2、GF3)对九株乳杆菌的增殖作用。以大蒜果聚糖为唯一碳源进行乳杆菌的体外发酵实验,并与2种商业益生元-低聚果糖Fructo-oligosaccharides(FOS)和菊糖(Inulin)做对比,以48h发酵液的pH和益生指标PrebioticIndex(PI)值作为评价指标,对大蒜果聚糖的益生元效应做出评估。结果显示,GF1对九株乳杆菌的PI值均达到0.6以上,且发酵液的pH有明显下降,优于FOS和Inulin,而GF2和GF3发酵液PI值以及pH的下降与FOS和Inulin基本相当,说明三种大蒜果聚糖均具有一定的益生元作用,且聚合度越低,益生元功能越强。结果还显示,副干酪乳杆菌对五种果聚糖(GF、FOS、Inulin)的PI值均达到0.6以上,且同型发酵产生大量乳酸,显示其利用果聚糖增殖和产酸能力突出。

The prebiotic effects of three garlic fructans（ GF1, GF2 and GF3 ）were evaluated in vitro by investigating the growth promotion effects of 9 lactobacillus strains, FOS and Inulin were introduced as references.The growth character（OD630） and the final pH of the cutture medium were determined after using garlic fructans as the carbon source.Results showed that GF, was extensively fermented by 9 strains of lactobacillus.The PI values were up to 0.6 and the final pH were significantly decreased,which were better than that by FOS and Inulin.The PI values and pH decreases of GF2 and GF3 were similar to FOS and Inulin.These results demonstrated that all the three garlic fructans had prebiotic effects, and the one with low molecular weight had better beneficial effects.Moreover, among these 9 Lactobacillus strains,the PI value of strain Lactobacillus paracasei, which was fermented by GF, FOS and Inulin,reached 0.6,and produced lactic acid.It had a prominent ability to ferment fructans.