真空冷冻干燥白菊的试验研究

摘要

In this study, edible White Chrysanthemum were taken as the object of study, using vacuum freeze dryer of type LGJ-25C. First of all, the eutectic and the co-melting point of White Chrysanthemum were mea-sured by the way of thermal resistance. The experimental result showed that the eutectic point of White Chrysanthemum was-20℃and the co-melting point of White Chrysanthemum was-8℃. Followed, on vacu-um freeze-drying machine, the final dry basis moisture content, the drying time of White Chrysanthemum, color and shape were researched by changing the heating temperature. The optimum drying White Chrysanthemum route of vacuum freeze-drying had two steps. Firstly the White Chrysanthemum was pre-freezed for 6 h in the cold trap, then the White Chrysanthemum was put into the drying chamber and sublimation dried for 15 h, deabsorp-tion dried for 14 h. The drying process maintained high vacuum degree, and the heating temperature of deabsorp-tion drying maintained 45 ℃. The research results can provide guidance for practical White Chrysanthemum freeze-drying.%以食用白菊为研究对象，在LGJ-25C型真空冷冻干燥机上对其进行真空冷冻干燥工艺的研究。首先通过热电阻法测取白菊的共晶点为-20℃，共熔点为-8℃；随后通过改变搁板加热温度，研究不同加热温度对白菊最终含水量、干燥时间、颜色及形状的影响，结果表明加热搁板温度45℃为最佳搁板温度；最后得出真空冷冻干燥法干燥白菊的最佳工艺路线为将白菊预冻6 h，然后放入干燥室中升华干燥15 h，再解析干燥14 h，解析干燥时加热温度为45℃。研究结果可为白菊的实际冷冻干燥生产提供指导。