制备高品质的紫淮山全粉, 有利于拓宽紫淮山的消费途径和提升产品价值。本文考察了固液比、进料流量和冻结温度对紫淮山全粉水分含量、溶解度和花色苷含量的影响, 通过四因素三水平正交试验, 优化了紫淮山全粉喷雾冷冻干燥工艺, 并对热风干燥、真空冷冻干燥、喷雾干燥、喷雾冷冻干燥这4种干燥方式制备的紫淮山全粉理化特性和抗氧化能力进行了比较。结果表明, 紫淮山冷冻喷雾干燥的最佳工艺条件为进料流量25 mL/min、固液比1∶1、冻结温度-30 ℃, 在此条件下得到的紫淮山全粉水分含量为3.89%、溶解度为23.12%、花色苷含量为13.28 mg/100 g。干燥方式对紫淮山全粉的物理性质、营养成分、活性成分和抗氧化能力的影响显著。

To increase the value and promoting consumption of purple yam, flour was prepared as a fast food with good flavor. The effects of main processing parameters, including ratio of solid to liquid, material flow and freeze temperature, on water content, solubility as well as anthocyanin content of yam flour during spray-freeze drying were studied. By using the orthogonal experimental method with four factors and three levels, the optimal parameters for the spray-freeze drying technology of yam flour was obtained. And the influences of spray-freeze drying, spray drying, freeze drying and hot air drying on the physical, nutritional and antioxidant properties of purple yam flour were studied. The results indicated that the optimum process parameters for drying yam flour were determined as follows: ratio of solid to liquid of 1∶1, material flow of 25 mL/min and freeze temperature of -30 ℃. Under above conditions, the water content, solubility and anthocyanin content of purple yam flour were 3.89%, 23.12%, 13.28 mg/100 g, respectively. Drying methods showed significant effects on the physical, nutritional and antioxidant properties of purple yam flours.