为解决冷藏运输中叶菜类存在的降温不均等问题，以上海青为例来研究叶菜各部位在添加相变材料的冷藏箱体中降温、低温存储及复温过程中的温度变化。结果表明，应用相变材料的冷藏箱体在降温过程中能缩小大叶脉与叶片处的温差，防止叶片冻伤；在低温存储过程中，能够减缓上海青各部位之间的温差波动；在升温过程中，相变材料的固液相变潜热能延缓箱体内部空间及上海青各部位的温度上升。在升温过程中，大叶脉、小叶脉及叶片处一直存在温差，且温差出现先增大后减小的趋势。综上，应用相变材料的冷藏箱体可减小上海青各部位温差波动，增加低温存储时间并减缓升温，有利于果蔬的冷藏保鲜。%An innovative refrigeration system incorporating phase change material ( PCM ) is proposed to overcome uneven cooling during refrigerated transportation of leafy vegetable .Taking Brassica chinensis L.as an example of leafy vegetable , its temperature change and distribution during cooling and warming process was systematically recorded and analyzed .It was shown that the temperature fluctuation during cooling process was significantly reduced to 2℃( P<0.01 ) when PCM was incorporated into the refrigerated container .The difference of temperature between main vein and small veins was also reduced .During the storage process , the temperature fluctuation was reduced up to 25.8%with PCM incorporation.Besides, the temperature increase during warming process was slowed down with addition of PCM.In summary, application of PCM into refrigerated container could reduce temperature fluctuation during refrigerated transportation and thus benefit the preservation and cold storage of vegetables and fruits .
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