卷心菜真空预冷方式的实验研究

Experimental study of vacuum cooling methods for cabbage

真空预冷是果蔬采摘后有效的预冷方式之一,具有冷却速度快、温度均匀等特点。本文以组织致密类蔬菜卷心菜为研究对象,通过实验找出其适合的真空预冷终压,并以此终压为实验结束压力,分别对卷心菜进行直接预冷、喷水预冷、喷水加保鲜膜和表面包覆吸水膜预冷实验研究。结果表明:通过采用吸水膜包覆卷心菜这种预冷方式,可以显著提高降温速率,缩短预冷时间,降低失水率,降低能耗。吸水膜包覆方式从初温27℃降低到5℃需要的时间比直接预冷少48%,失水率降低76.7%,能耗降低45%。因此,采用吸水膜包覆是提高卷心菜降温速率,降低失水率的有效方法。

Vacuum cooling is one of the effective pre-cooling methods,which has the advantages of rapid cooling rate and uniform temperature.Cabbage was used in this paper as research object to study the suitable vacuum chamber cooling pressure by controlling different vacuum cooling end pressure.Using various vacuum cooling methods as direct vacuum cooling,spray water vacuum cooling, spray water and preserve film vacuum cooling and water absorbent film package vacuum cooling, the results show that vegetables packaged with water absorbent film have the fastest temperature decreasing rate, the shortest cooling time and the lowest water loss rate and energy c0nsumption.The spending time of cabbage temperature decreasing from 27℃ to 5℃ in this vacuum cooling method is 48% less than the method of direct vacuum cooling,and the water loss rate reduced 76.7% and the energy consumption reduced 45%.So,water absorbent film package vacuum cooling is an effective method to improve temperature decreasing rate and reduce water loss during vacuum cooling.