紫甘薯饮料制备工艺研究

以紫甘薯为原料探讨紫甘薯饮料制备的工艺条件。比较α- 淀粉酶液化和高温液化两种方式对淀粉液化的效果，并进一步添加糖化酶进行淀粉糖化，同时探讨各工序对花色苷的影响，以饮料的可溶性固形物增长率、吸光度及色差值为考察指标。结果表明：鲜薯用两倍水打浆，加入0.020g/100mL α- 淀粉酶于70℃条件下酶解40min，再添加0.04g/100mL 的糖化酶在pH5.0 条件下糖化40min，既可获得理想的淀粉水解效果，又可尽量减少花色苷的损失。较好的饮料配方为30% 甘薯原汁、8% 蔗糖、0.05% 柠檬酸，其余为软水。采用该工艺条件可制备色香味俱佳的紫甘薯饮料。

Development of a Purple Sweet Potato Beverage

Purple sweet potato was used as the raw material to investigate the preparation processing of purple sweet potato beverage. The effects of sweet potato starch liquefaction by α-amylase and high temperature were compared, and then the starch was glycosylated by glucoamylase. The effect of treatment processing on anthocyanin was also explored on the basis of soluble solids, absorbance and color difference. Results indicated that the favorable hydrolysis of starch and the minimal loss of anthocyanin in purple sweet potato beverage could be achieved through following process: pulping of steamed sweet potato with water in double mass, then treating with 0.020 g/100mL α -amylase hydrolysis at 70 ℃ for 40 min, and followed by glycosylating with 0.04 g/100mL glucoamylase for hydrolysis at pH 5.0 for 40 min. An excellent beverage with attractive color, flavor and taste was developed by 30% purple sweet potato juice, 8% sucrose and 0.05% citric acid in soft water.