Vinegar With Spraying Mechanism And Prevention Of Plaque In The Fermentation

Vinegar pouring fermentation is an advanced vinegar brewing way, which is applied widely in the world. The raw material is low concentration ethyl alcohol fluid in overseas, but in our country, following traditional vinegar brewing, raw material is rice, which is saccharified and ethyl alcohol fermented before vinegar pouring fermentation. Pouring fermentation vinegar has obtained a very good economic efficiency. But now, in our country the universal serious problem with vinegar pouring fermentation is the forming of membrane like Leather, which blocks up the interspace among stuff. In this condition, the fermentation must be terminated after one to three months fermentation because air and fermentation fluid cannot flow normally. Domestic reports were few about this question.The research indicated that the bacterial membrane was composed of bacterial cellulose(BC), which was produced by the pollution of microbe. Our purpose was to solve the above problem radically, we collected some liquid and stuff samples from Guiyang Wei Chun Yuan food limited company. We discovered the effective preventing and controlling methods of BC through researching on the producing mechanism of BC.The main experiment and experimental results as follows:(1) Mechanism research of bacterial membrane formation in the process of vinegar pouring fermentationa Obtained a good acetobacter strain A₁₁ and a BC producing strain Y₂₂ by separating liquid and stuff samples. Strain A₁₁ produced acetic acid well without bacterial membrane formation; strain Y₂₂ was acetobacter xylinum according to it's shape and physiological biochemistry characteristics, and the membrane was composed of BC.b The most suitable growth and producing acetic acid temperature of strain A₁₁ were 37℃and 30℃, respectively. The most suitable growth and BC synthesis temperature of strain Y₂₂ were all 30℃. BC output achieved high when vaccination amount of strain Y₂₂ was 8%. Therefore, BC had different influence in the process of vinegar pouring fermentation with different amount of Y₂₂ pollution.(2) Preventing and controlling research of BC in the process of vinegar pouring fermentation a The addition of acidic cellulase had no influence to acetic acid producing when A₁₁ and Y₂₂ were cultivated mixly in liquid medium and rice saccharification fluid, respectively. 0.08% acidic cellulase could prevent BC producing. Adding phosphoric acid diesterase also had no influence to acetic acid producing. When acetic acid content increased, phosphoric acid diesterase activity decreased in the process of fermentation, so it couldn't restrain the synthesis of BC completely. Adding acidic cellulase and phosphoric acid diesterase simultaneously had no influence to acetic acid producing. two kinds of enzymes had cooperating function to preventing BC formation.b Through the orthogonal experiment and SAS8.1 software analysis to the result, we obtained a model equation: E = 13.8628 - 2.8917A + 0.2777 B - 0.2296 C + 0.0242 D. According to the polluted number (CFU/mL) of strain Y₂₂, the enzymes amount was determined with the model equation. So, BC could be prevented in the process of fermentation effectively.c if BC had formatted in the process of fermentation, optimum amount acidic cellulase was added according to the BC pollution degree.