混菌发酵产酶活性与苹果酒风味物质构成的相关性分析

为研究苹果酒发酵过程中酶活性对苹果酒香气品质的影响，对德尔布有孢圆酵母（Torulaspora delbrueckii）和酿酒酵母（Saccharomyces cerevisiae）单独和混菌发酵过程中β-葡萄糖苷酶、果胶酶、酸性蛋白酶及α-淀粉酶活性及苹果酒香气成分进行测定，并通过建立偏最小二乘回归（PLSR）分析模型对苹果酒酒精发酵阶段酶活性与风味物质之间的相关性进行分析。结果表明，混合发酵方式1、2条件下β-葡萄糖苷酶、果胶酶曲线下面积（AUC）最高，分别为15.11 nmol/（min·mL）、19.71 mg/（h·mL），混合发酵有利于增加苹果酒香气成分的复杂性。相关性分析表明，β-葡萄糖苷酶与27种挥发性物质存在显著相关性（P＜0.05），果胶酶、蛋白酶与18种挥发性物质存在显著相关性（P＜0.05），对挥发性物质的形成有较大影响，而α-淀粉酶则与各组分无明显的相关性（P＞0.05）。

Correlation analysis between enzymatic activity and flavor substances composition in cider by mixed-strain fermentation

The activities of β-glucosidase, pectinase, acid protease and α-amylase and aroma components during cider fermentation by single strain and mixed-strain Torulaspora delbrueckii and Saccharomyces cerevisiae were determined, in order to study the effects of enzyme activity on the aromatic quality of cider during the fermentation, and the correlation between enzymatic activities and flavor substances in the alcoholic fermentation of cider was analyzed by establishing a partial least squares regression (PLSR) model. The results showed that the area under curve (AUC) of β-glucosidase and pectinase in the mixed-strain fermentation method 1 and 2 was the highest, which was 15.11 nmol/(min·ml) and 19.71 mg/(h·ml), respectively, indicating the mixed-strain fermentation was beneficial to increase the complexity of aroma components of cider. Correlation analysis showed that β-glucosidase was significantly correlated with 27 kinds of volatile substances (P＜0.05), and pectinase and protease were significantly correlated with 18 volatile substances (P＜0.05), which had a great effect on the formation of volatile substances, while α-amylase had no significant correlation with each component (P＞0.05).