Separation And Indentification Of Lactic Acid Bacteria And Its Application In Vinegar Fermentation

Vinegar is an acid of Chinese traditional condiment, the essential constituents of organic acid are acetic acid and lactic acid.Vinegar which has larger proportion of non volatile acid is less stimulating and softer taste, and lactic acid is the main nonvolatile acid. In order to improve the poor taste of the liquid fermented vinegar and increase the amount of non-volatile acid, in this study, lactic acid bacteria which is conducive to the lactic acid bacteria fermentation of vinegar is separated from fermented grains of duliu vinegar and their performance was evaluated together with yeast in liquid pure breed fermentation fermenting. The purpose of this study on lactic acid bacteria is to improve the taste and enhance the flavor of vinegar.This article use Pour plate method isolated from fermented grains in fermentation and purification filters are a good strain of lactic acid bacteria by Biolog microbial identification system identified as Weissella minor. Access 1% of lactic acid bacteria in a liquid medium at different time periods measured OD values and pH of culture medium identification of lactic acid bacteria best activation time of 15 h; measuring lactic acid bacteria strains in different conditions of pH liquid 24 h OD values, measured the most appropriate pH condition is 28,30,33,37℃ under the lactic acid bacteria, strains of lactic acid bacteria liquid measuring OD values after 24 h, the measured 30℃ (the most suitable temperature for vinegar fermentation) the development of strains of lactic acid bacteria liquid when the OD value of 37℃ (optimum incubation temperature of lactic acid bacteria) are similar. If lactic acid bacteria and yeast are cultivated together, the decreasing rate of reducing sugar is similar to the respective addition rate of yeast and to the rate of ethanol yields. Yeast in liquid medium access 0,0.5,1,1.5,2,2.5 g/100 mL acid, cultivation 24 h number after number of yeasts, lactic acid content below 0.5g/100mL can promote yeast growth. Lactic acid bacteria in a liquid medium into 0,2,4,6,8 mL/100 mL alcohol, alcohol content less than 4 mL/100mL lactic acid bacteria less suppressed.Determination of organic acids by high performance liquid chromatography, measured in the liquid fermentation of lactic acid bacteria in tests the best inoculum for 5×105/mL, this yields the highest inoculum of organic acids. In the fermentation of bacteria in collaboration with, vinegar grains which was processed with lactic acid bacteria was compared with the one without lactic acid bacteria. Lactic acid content by 2.1 times, citric acid by 4.5 times. After fermentation, total acid content of the former 6.72 g/100g, which is 6.43 g/100 g; former 0.13 g/100 g amino nitrogen content which is 0.12 g/100 g. Lactic acid content is 2.1 times of the former for the latter. Use SPME-PA method to detect fermentation vinegar grains sample aroma components, ester flavors rose to 40.15%. These results indicate that the addition of lactic acid bacteria is beneficial to improve the flavor of liquid fermentation vinegar.