葡萄糯米香醋发酵工艺的优化

Optimization of fermentation process of grape-glutinous rice aromatic vinegar

该研究以葡萄和糯米为原料制备葡萄糯米香醋,以酒精度和感官评分为评价指标,采用正交试验设计优化其酒精发酵工艺条件;以总酸含量和感官评分为评价指标,优化其醋酸发酵工艺条件,并对该产品的挥发性成分、理化指标及感官品质进行分析。结果表明,最佳酒精发酵工艺条件为:葡萄与糯米质量比2∶1、初始糖度23%、葡萄酒高活性干酵母添加量0.22%、发酵温度28℃;最佳醋酸发酵工艺条件为:初始酒精度7%vol、醋酸菌(Acetobacter aceti)接种量5%、发酵温度30℃。在此优化条件下,葡萄糯米香醋共检出31种挥发性成分,其中醇类7种、醛类3种、酸类7种、酯类13种、苯类1种,总酸、总酯含量分别为4.70 g/100 mL、3.18 g/100 mL,葡萄糯米香醋呈红褐色、澄清透亮,口感醇厚、酸甜柔和,具有浓郁的果香和醋香。

Grape-glutinous rice aromatic vinegar was prepared using grape and glutinous rice as raw materials,taking alcohol content and sensory scores as evaluation indexes,the ethanol fermentation conditions were optimized by orthogonal experimental design.Using total acid content and sensory scores as evaluation indexes,acetic acid fermentation process conditions were optimized,and the volatile components,physicochemical indexes and sensory quality of the product were analyzed.The results showed that the optimal alcohol fermentation conditions were as follows:mass ratio of grape and glutinous rice 2∶1,initial sugar content 23%,wine active dry yeast addition 0.22%and fermentation temperature 28℃.The optimum acetic acid fermentation conditions were as follows:initial alcohol content 7%,Acetobacter aceti inoculum 5%and fermentation temperature 30℃.A total of 31 volatile components of grape-glutinous rice aromatic vinegar were detected in the brewing products under these optimal conditions,including 7 alcohols,3 aldehydes,7 acids,13 esters and 1 benzene.The contents of total acids and total esters were 4.70 g/100 ml and 3.18 g/100 ml,respectively.The grape-glutinous rice aromatic vinegar was reddish brown,clear and bright,mellow taste,soft sweet and sour,with strong fruit and vinegar flavor.