产叶酸乳酸菌的筛选及对发酵乳的影响

为筛选出高产叶酸的乳酸菌并研究该乳酸菌对发酵乳的影响,采用高效液相色谱(HPLC)法从5种乳酸菌菌株:植物乳杆菌、嗜热链球菌、保加利亚乳杆菌、干酪乳杆菌、嗜酸乳杆菌的发酵液中检测叶酸含量,并通过检测复合发酵乳的pH、持水力、质构特性和感官特性来研究产叶酸的乳酸菌对发酵乳品质的影响。结果表明:植物乳杆菌产叶酸量最高,其次是嗜酸乳杆菌,分别为51.40和34.77 μg/mL。并且以基础菌发酵乳为对照组,添加产叶酸乳杆菌发酵乳为实验组,实验组与对照组相比,其质构特性和感官品质会提高,同时pH也显著下降(p<0.05)。本实验为开发功能性发酵乳提供了一定的理论依据。

Screening of producing folic acid Lactobacillus and its effect on fermented milk

In order to screen out lactic acid bacteria with high folate production and study the effect of Lactobacillus on fermented milk, five strains of Lactobacillus (L. plantarum, Streptococcus thermophilus, L. bulgaricus, L. casei, L. acidophilus) were screened for the aim of high folic acid yield by High Performance Liquid Chromatography (HPLC) method. Meanwhile, the effect of folic acid producing Lactobacillus on the quality of fermented milk was also investigated through the bacteria complex made of fermentation fermented yogurt, after the measured pH value, water holding capacity, texture properties and sensory characteristics. Results showed that L. plantarum has a significant potential capacity of folic acid production, followed by L. acidophilus, with the concentration of 51.40 μg·mL-1 and 34.77 μg·mL-1, respectively. With basal bacteria fermented as the control group, folic acid producing bacterium was added as the experimental group. The results indicated that the acidity and texture of the yogurt were higher in the test group than that of the control group. pH value was also significantly lower than the control group (p<0.05). This experiment provides a theoretical basis for the development of functional fermented milk.