Screening Of Excellent Acetic Acid Bacteria Of Black Currant Fruit Vinegar And It’s Fermentation Technology

A strain appropriate for black currant vinegar fermentation was screened from waste liquor after natural alcohol fermentation and acetic fermentation with raw meterial of black currant, a battery of studies such as compositions and conditions of culture medium and fermentation conditions for the black currant vinegar fermentation, analysis of aromatic composition in vinegar, clarification process of vinegar were researched by then, and there search results were as follows:(1) Screening and characterization of a strain for black currant vinegarAS1.41as control strain,182strains were isolated from liquor made after natural alcohol fermentation and acetic fermentation as the separation source, in which three excellent strains A-39、A-81、A-168were selected and A-168had the highest homology(100%) with Ga. hansenii NBRC14820belonged to Gluconacetobacter hansenii through physiological, biochemical and molecular biology identification, then it was picked as the research strain based on an overall consideration of various factors.(2) Optimization of cultivation conditions of black currant vinegar strainThe optimal seed medium components and cultivation conditions of A-168were obtained by single factors and central composite designs, and the optimal results of seed medium components were as follows: maltose1.34%, yeast extract1.16%, ethanol2.77%, acetic acid0.54%, K2HPO40.34%, CaCO31.02%. The optimal culture conditions were pH5.5, starter age22h, inoculating amount9%, revolving amount150r/min, volume of medium1/6.(3) Optimization of fermentation conditions of black currant vinegarBlack currant vinegar was produced using black currant wine as raw material and strain A-168, then the fermentation process was optimizated according to singal factors and Plackett-Burman using to select significant factors, with the Box-Benhnken center-united experimental design principles and response surface analysis adopted to determine optimal fermentation conditions of blackcurrant vinegar. The optimal fermentation conditions were as follows:fermentation temperature32℃, inoculating amount9%, alcohol5.7%(v/v), initial pH value4.5, volume of medium97mL/500mL,revolving amount126r/min, initial amount of sugar5°BX.(4) Analysis of aromatic composition in blackcurrant vinegar by GC/MS89kinds of aroma compounds from black currant vinegar aroma compounds extracted by Solid phase micro extraction and analyzed by GC/MS were identified by mass spectra database searching technology, and35kinds of aroma compounds that matching score above80including3kinds of acids,7kinds of esters,3kinds of phenols,4kinds of alcohols,13kinds of hydrocarbon,4kinds of aldehydes and ketones,1kind of quinone, were81.65%in volatile constituents, in which acids is of the high content33.38%, followed by easters26.44%, phenols8.69%, alcohols4.91%, hydrocarbon4.61%, aldehydes and ketones3.28%, quinone0.34%.(5)Study on clarification condition of black current vinegarClarificated by attapulgite after single factor of the best clarifier for blackcurrent vinegar, L9(34) orthogonal experiment design was performed with factors of attapulgite clarifying time (h), attapulgite clarifying temperature (℃), attapulgite amount (g/L) and index of fruit vinegar transmission rate. The optimum condition was12g/L adding admeasure of attapulgite, attapulgite clarifying temperature40℃, attapulgite clarifying time5h.