Effects of Lactobacillus Enhanced Fermentation on the Antioxidant Characteristics and Flavor of Tartary Buckwheat Jiaosu

In order to improve the taste and antioxidant capacity of Tartary buckwheat. Using reducing power and SOD activity as main indexes, four strains of Lactobacillus plantarum (LBS8, MRS5), Lactobacillus paracareflora (MC6) and Lactobacillus paracei (SL1) were investigated to enhance the fermentation of Tartary buckwheat Jiaosu. An excellent strain was screened out and the effects of inoculation amount, initial sugar degree, fermentation temperature and solid-liquid ratio on the fermentation process of Tartary buckwheat were studied. The fermentation process of Tartary buckwheat was optimized by completely randomalized design and orthogonal experimental design. The results showed that LBS8 fermentation Tartary buckwheat had strong reducing ability and SOD activity. Inoculation amount of 6%, initial sugar degree of 16°Brix, fermentation temperature of 32 ℃, solid-liquid ratio of 1:7 were the optimum conditions. Under this condition, the reducing power of the obtained Jiaosu was 0.753 mg/mL, the SOD activity was 272.12 U/mL, the total content of flavone was 0.521 mg/mL, the total content of phenol was 2.75 mg/mL, and the content of glutathione was 0.273 mg/mL. Compared with the control group, there were significant improvements. Through GC-MS analysis, tartary buckwheat Jiaosu contained characteristic aroma substances such as ethyl acetate, ethyl linoleate, ethyl undecanoate, and butanedione, giving tartary buckwheat Jiaosu a unique flavor. Compared with commercially available starter cultures, the total flavonoids, polyphenols, glutathione, reducing power and antioxidant capacity of Lactobacillus plantarum enhanced fermentation increased by 247%, 2%, 36.5%, 30.73% and 30.09%, respectively. The flavor and taste of Lactobacillus plantarum enhanced fermentation was richer than that of commercially available starter cultures. The results indicated that inoculation with Lactobacillus plantarum fermentation was beneficial to improve the quality of Tartary buckwheat fermentation.