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.