紫色马铃薯酒发酵工艺优化及主发酵期花青素与色泽的动态变化

以紫色马铃薯为原料，在单因素的基础上，通过响应面法对紫色马铃薯酒的发酵工艺参数进行优化。最佳发酵工艺参数为:马铃薯与面粉比1:0.6、料水比1:1 (g/mL)、α-淀粉酶添加量8.5 U/g、酒曲添加量0.45%。此工艺在28 ℃下发酵14 d，得到的紫色马铃薯酒酒精度13.5%vol，花青素含量166.34 mg/mL，酒体澄清透明呈紫红色，酸甜适中，有独特酒香，综合感官评定得分90分。测定主发酵期花青素和色泽的动态变化，分析表明，紫色马铃薯酒在发酵过程中花青素呈现先上升后下降的趋势，色度呈现先下降后趋于平缓的趋势，色调则与之相反。聚合色度和褐变指数总体均呈现逐渐上升的趋势。试验结果为工业化生产紫色马铃薯酒提供理论依据。

Optimization of Fermentation Technology of Purple Potato Wine and Dynamic Changes of Anthocyanin and Color in Main Fermentation Period

Using purple potato as raw material, on the basis of single factor, the fermentation parameters of purple potato wine were optimized by response surface methodology. The optimum fermentation parameters were as follows: the ratio of potato to flour was 1:0.6, the ratio of material to water was 1:1 (g/mL), the dosage of alpha-amylase was 8.5 U/g, the dosage of distiller's yeast was 0.45%, and the fermentation was carried out at 28 ℃ for 14 days. The purple potato wine obtained by this process has an alcohol content of 13.5%vol and anthocyanin content of 166.34 mg/mL. The wine was clear and transparent, purplish red, with moderate sweet and sour taste. The comprehensive sensory evaluation score was 90 points. The dynamic changes of anthocyanin and color in the main fermentation period were measured. The analysis showed that the anthocyanin in the purple potato wine increases first and then decreases, while the chroma decreases first and then tends to be flat, while the hue was opposite. The overall polymerization chromaticity and browning index showed a gradual upward trend. The experimental results provide theoretical basis for industrial production of purple potato wine.