Screening of High Oxalate-degrading Lactic Acid Bacterial Strains and Its Characteristics in Yogurt Fermentation

In this paper, 49 strains of lactic acid bacteria from self-made yogurt, pickles, fermented head and other characteristic fermented food were selected as candidate strains. The oxalate degradation ability and tolerance of simulated gastrointestinal tract in vitro were determined by spectrophotometry, and the characteristics of fermented yogurt were evaluated by principal component analysis. The result showed that the oxalate-degradation rate of 9 strains was more than 70%, the highest was 86.96%. Among them, the survival rate of the strains “Sichuan Pixian A1”, “Ewenki”, “Luqing6” in pH3.0 acid solution, artificial simulated gastric juice, bile salt solution and artificial simulated intestinal juice was more than 50%. The sensory evaluation, holding water capacity, titratable acidity, post-acidity, rupture force, hardness, gumminess, cohesiveness, chewiness and springiness of yoghurt fermented with the strains “Ewenki” and “Luqing6” were better. The strains “Ewenki” and “Luqing6” were Weissella cibaria and Lactobacillus paracasei. They could efficiently degrade oxalate and tolerate gastrointestinal environment, and at the same time, they had good fermentation characteristics in yoghurt and would be used as candidate strains for the development of functional yoghurt.