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真空冷却中上海青下表皮对其传热传质的影响*
宋晓燕刘宝林*
(上海理工大学低温生物与食品冷冻研究所,上海,200093)

摘要研究了上海青下表皮的结构特性对其真空冷却程中传热传质的影响。结果表明:下表皮能有效防止辐射热和
对流热造成的温升;由于水蒸气穿过气孔时属于薄壁孔粘滞流,所以,当真空室的压力与叶子内部的饱和水蒸气压
力的比值小于时,继续降低真空室压力没有意义;如果将上海青冷却到 4℃,真空室的终压不能低于 444Pa。
关键词真空冷却,下表皮,气孔,温度,压力
中图分类号: 文献标识码:A

Effect of Lower Epidermis of Shanghaiqing on Its Heat and Mass
Transfer during Vacuum Cooling Process
Song Xiao-yan, Liu Bao-lin*
Institute of Cryobiology and Food Freezing Engineering, University of Shanghai for Science and
Technology, Shanghai, 200093
ABSTRACT Effect of lower epidermis’s structural characteristics of Shanghaiqing on its heat and mass transfer during
vacuum pre-cooling process was studied. The results showed that: lower epidermis can availably avoid temperature rising
caused by the radiant heat and convective heat; since the flow state of water vapor passing through the thin stoma is in the
range of viscous flow, it is invalid to reduce the pressure of vacuum chamber if pressure ratio of vacuum chamber to internal
leaf is less than ; if it is intend to cool Shanghaiqing to 4℃, final pressure for vacuum chamber should not be set below
444Pa.
Keywords Vacuum cooling; Lower epidermis; Stoma; Temperature; Pressure

真空冷却是通过在低压下蒸发水分来制取当日采摘的上海青,购于图门路菜市场,用
冷量的一种制冷技术[1],现如今已经被广泛的食品专用 PE 保鲜膜包装后 10 分钟内送至实验
应用于多种食品的初加工过程中,例如熟肉的室。
快速冷