典型中华菜肴鱼香肉丝的真空冷冻干燥工艺研究

Vacuum freeze drying of typical chinese food of yuxiangrousi

以鱼香肉丝这一典型的中华菜肴为对象,通过正交实验求出了最佳真空冷冻干燥工艺参数,即物料铺放厚度5mm、升华干燥的真空度140Pa、解析干燥的真空度30Pa、解析时加热板温度20℃。试验得出的影响冷冻干燥的主要工艺因素其次序为:加热板温度、物料铺放厚度、升华压力和解析压力。同时还求出了这种菜肴的复水工艺参数,即复水量为干制品含水率的140%～150%,复水温度65—85℃,复水时间20～30min。最后通过本研究建立的数学模型对干燥时间进行了验证。

The optimum set of processing parameters obtained through the orthogonal experiments for the typical Chinese dish of Yuxiangrousi are 5mm of bed height,140Pa of chamber pressure during the sublimation process,30Pa of chamber pressure during the desorption process,and 20℃ of heating board temperature.The crucial factors influencing the process are heating board temperature,material thickness,sublimation and desorption pressures in sequence of importance.Moreover,the suitable rehydration parameters obtained from the experiments are as follows:the amount of moisture for rehydration is 40～50% more than that contained in the dried material before rehydration;the temperature of rehydration water is about 65～85℃;and the desorption time is about 20～30min.A mathematical model developed in this work was used to predict the time of vacuum freeze drying.