文章基本信息

标题：Theoretical Simulation and Experimental Study on Effect of Vacuum Pre-Cooling for Postharvest Leaf Lettuce
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作者：Enhai Liu ; Xiaobo Hu ; Shengyong Liu 等
期刊名称：Journal of Food and Nutrition Research
印刷版ISSN：2333-1119
电子版ISSN：2333-1240
出版年度：2014
卷号：2
期号：8
页码：443-449
DOI：10.12691/jfnr-2-8-3
语种：English
出版社：Science and Education Publishing
摘要：The effect of vacuum pre-cooling process on leaf lettuce was a complex process of heat and mass transfers. Based on the properties of leaf lettuce in vacuum pre-cooling process, an unsteady computation model was constructed to analyze the factors affecting vacuum pre-cooling. Some factors such as the pre-cooling temperature, pressure and quantity of the spray-applied water were verified throughout the experiment. The study showed that the measured and simulated values were basically the same, and the overall trend was similar. The lower the vacuum pressure, the greater the cooling rate lettuce and water loss rate. In this experiment, the water volume and pre-cooling pressure were the important factors during vacuum pre-cooling. This paper discovered that the quantities of leaf lettuce covered with water were equal to 4.211–5.977% of the total sample mass and the mass loss of the sample was 1.987–2.873%. Under pre-cooling pressure of 600, 1000, and 1500 Pa, the mass loss was 2.758, 2.701 and 1.929%. After that, the results of calculation indicated that the quantities of capture water of the water-catcher was 1.607–2.567 g, and the cooling capacity of the total sample was 3.722–5.946W in vacuum pre-cooling process. The results reveal that the model of leaf lettuce was fitted and it was confirmed by the experimental data.
关键词： theoretical simulation; model; leaf lettuce; vacuum pre-cooling; cooling capacity