Improved Screening Of Probiotic Lactic Acid Bacteria Specific For Fruit-vegetable Beverages Fermentation And Its Fermentation Technology

China is the largest source of fruits and vegetables, but the marketing situation is severe, plus the attention towards beverage is turning to natural, nutritious, healthy aspects. Accordingly, development of fruits and vegetables drinking with health function using bio-fermentation technology is badly needed. Screening and fermentation of probiotic lactic acid bacteria was studied, fruits and vegetables drinking fermented by lactic acid bacteria was developed. It could ease the marketing situation, and also hit the target of transforming bulk fruits and vegetables with high value and high efficiency, besides, it meets the demand of consumers. The main research contents and results were as follows:(1) Lactobacillus plantarum, which was screened from various fermented fruits and vegetables, was reinforced by using of culture medium with high concentrations of bile salts and acid, it would have the very strong ability which resistance to bile salts and acid, and could pass through the gastrointestinal environment better. After the morphological and physiological and biochemical identification, furthermore, it compared with control strain CICC6092in terms of performance test, a fine strain had been obtained, which would get used to ferment fruit and vegetable fast.(2) Lactobacillus plantarum NCU116was investigated for tolerance in a simulated human digestive tract environment artificial gastric fluids, artificial intestinal fluids, bile salt and high concentration salt environment. The results showed that survival rate of Lactobacillus plantarum NCU116reached32.62%and45.76%respectively in pH values for1.5and2.5of artificial gastric fluid. The count of living bacterium changed gently between in three hours in pH values above3.5of artificial gastric fluid. Survival rate achieved49.63%after4h in artificial intestinal fluid, and the concentration of residual living bacterium was still above108CFU/mL. After24h, viable bacteria count reduced with the increase of mass fraction of bile salt, while0.30g/100mL, living bacterium concentration still remained at108CFU/mL. In salt environment with sodium chloride of1-8g/100mL for24h, viable bacteria count lowered slightly with the increase of mass fraction of sodium chloride. These showed that Lactobacillus plantarum NCU116had excellent tolerance in artificial gastric fluids, artificial intestinal fluids, bile salt and high concentration salt, making a bright future for its application in food industry.(3) The end-point of banana juice fermentation was determined by measuring growth curve of Lactobacillus plantarum NCU116, and we compared the effect of different sweeteners on the fermentation of banana juice. The results showed that it was in logarithmic phase when the period of8-11h, and in stationary phase when11h-16h, its viable count reached the most after fermented14h, it began to enter into decline phase when16h, so we could choose14h to be the end-point of banana juice fermentation. There is no significant effect of different sweeteners on the fermentation of banana juice, so it might be make use of banana to be the main nutriment.(4) The production process and formula for fermented beverage was studied by comparing single-factor experiment and orthogonal experiment. According to the sensory evaluation and viable count, pH value, acidity, reducing sugar content, the optimal fermentation technology were found as follows:banana added25%, white granulated sugar5%,3%glucose, the best compound color fixatives (l%o Vitamin c+1‰citric acid), inoculation amount10-4, fermenting14h at32℃.