速冻紫薯丁制备工艺研究

以新鲜紫薯为原料,将紫薯切丁后经护色、速冻后冻藏制备速冻紫薯丁。以护色工艺作为研究重点,分别采用热烫护色,海藻酸钠和壳聚糖涂膜护色,并以不护色直接真空包装作为空白对照组进行实验。以冻藏过程中PPO活性、褐变强度、色泽、糖类物质(淀粉,还原糖,总糖)的变化作为衡量指标,优选制备工艺。结果表明:1.6%的海藻酸钠涂膜护色后再经速冻后冻藏是最佳的速冻紫薯丁制备工艺,保质期可达90d。

Preparation of quick-frozen purple sweet potato cubes

The preparation technology of quick - frozen purple sweet cubes was studied. Color protection technology was used after purple sweet potatoes were cut into cubes,then the cubes were storaged in a frozen house after quick - freezing. In this experiment,color protection was a research focus. Taking color protection by means of blanching,sodium alginate solution coating and chitosan solution coating respectively together with a vacuum - packed cubes as a control group. During frozen storage,the change of polyphenol oxidase activity(PPO),browning intensity,color and carbohydrate content(including starch,sugar and total sugar)in purple sweet cubes were taken as index to select the preparing process. The results showed that the purple sweet potato cubes coating by 1. 6% sodium alginate solution for color protection and then followed by frozen storage after quick- freeze would have the best quality,whose shelf life was up to 90d.