Optimization of liquid submerged fermentation technology of apricot vinegar

The alcoholic fermentation and acetic acid liquid fermentation technology of apricot vinegar were studied.The alcoholic fermentation was optimized by means of L9(34) orthogonal test.The optimized result was 16°Bx the initial Brix,3% inoculation volume of yeast and fermentation temperature 30 ℃.The alcohol content was 8.6% under the optimized condition.Response surface methodologu was applied to study variation regularity of apricot acetic acid fermentation and to optimize the technical parameters with the four factors quadratic currency rotational composite experiment.The result showed that initial alcohol concentrarion,inoculation volume of acetic acid bacteria,fermentation time and shaker rotate speed had a highly significant influence on total acid content of apricot vinegar.The optimal fermentation parameters were obtained as: initial alcohol concentrarion 6.7%,13% inoculation volume of acetic acid bacteria,fermentation time 34 ℃ and shaker rotate speed 153 r/min.Under the condition,apricot vinegar had 7.11 g/100 mL total acid content(measured by the amount of acetic acid) and 6.23 g/100 mL volatile acid.