Study on in Vitro Functional Characteristics of Three Strains of Lactobacillus in Fruit and Vegetable Fermentation Broth

Taking 3 strains of Lactobacillus isolated from fruits and vegetables natural fermentation broth as the object, the surface characteristics of Lactobacillus were analyzed by measuring the surface hydrophobicity and self-aggregation rate; DPPH free radical scavenging ability, ABTS free radical scavenging ability and iron reducing ability were used as indexes to analyze the difference of antioxidant ability of three Lactobacillus strains in vitro; to evaluate the functional activity of Lactobacillus using cholesterol and nitrite degradation as indicators. The results showed that among the three strains, L3 had good surface hydrophobicity and self-aggregation rate, which were 57.7% and 95.2% (24 h) respectively; The supernatants of the three strains had stronger DPPH radical (>90%) and hydroxyl radical clearance (>68%) and reduction ability (>1.0), among which L1 and L3 supernatant had stronger hydroxyl radical clearance, nearly 90% and L2 had stronger anti-lipid peroxidation ability (>37%); Lactobacillus almost completely degraded 200 mg/L NaNO₂ within 48 h; The supernatants of the three strains had good cholesterol degradation ability (>19%), and their active substances were mainly proteins and polysaccharides. In summary, the three strains of Lactobacillus isolated from the fermentation broth of fruits and vegetables show good probiotic properties, which can lay a solid foundation for the development of functional fermented foods.