Abstract:Solid state fermentation is a distinctive technology for vinegarmaking. In general, the vinegar quality was evaluated by the contents of nonvolatile acid and total acid. The relationships between the contents of alcohol dehydrogenase (ADH) activity from 56 different fermentation seed tanks and the contents of nonvolatile acid and total acid from 56 different vaccination fermentation tanks were analyzed. The result showed that, when ADH activity values were controlled in 600~700U/mL, the vinegar substrate would showa good performance in quality. Whats more, the olfactory visualization sensor combined with backpropagation artificial neural network (BP-ANN) was used to test the ADH activity and predict nonvolatile acid and total acid. The result showed that the value of correlation coefficient of ADH activity, nonvolatile acid and total acid were 0.7816, 0.8447 and 0.9463, respectively. Therefore, the olfactory visualization sensor combined with BP-ANN could be well used in the prediction of physicochemical index for vinegar substrate.