Establishment of energy saving precooling transportation method for vegetables with package icing

包装结冰法预冷设备费用低廉，是一种经济有效的预冷方法。我们研究了适合这种方法的蔬菜，以及在不同外部温度的聚苯乙烯泡沫容器中冰的保存期。针对开发的用于运输花椰菜包装糖霜的聚苯乙烯泡沫容器，我们在与市场配送条件相似的条件下，测量了在不放置蔬菜的情况下进行包装糖霜时的箱内温度变化。根据测量结果计算的传热量揭示了外部温度与冰的剩余时间之间的关系有一定的趋势。将装有红萝卜的泡沫塑料容器放置在恒温箱中，温度分别为5、15和25个<s:1>℃，研究了冰量、红萝卜的温度下降与箱内空气量、红萝卜的热容量和泡沫塑料的保温性能之间的关系。结果分析表明，计算值与实测值基本吻合。我们将茄子、菠菜、黄瓜和白菜放入聚苯乙烯泡沫容器中，在蔬菜表面和下面放置一些冰，并分析了外部温度和冰的位置与蔬菜新鲜度的关系。结果表明，蔬菜的温度随冰的位置而变化，蔬菜的冷却速度随冰的位置和外界温度的不同而不同。在研究水冷的同时，我们还研究了空气冷却、真空冷却和不冷却对日本萝卜、西兰花和菠菜新鲜度的影响。日本萝卜减重最少。因此，水冷是最适合的。花椰菜经水冷处理后，重量几乎没有下降，但颜色变化很大。真空冷却后的西兰花减重效果明显，颜色变化不大。对于菠菜，它在水冷处理中表现出最好的效果，而且几乎没有减轻体重。少

Package icing method results in inexpensive facilities expenses for precooling, and thus is an economically excellent precooling method. We examined vegetables that are suitable to this method and the retaining period of ice in polystirene foam containers with various external temperatures.Regarding the polystirene foam container developed for package icing for the transportation of broccoli, we measured the temperature change in the box when package icing is applied without putting vegetables under the conditions similar to those of the market distribution. The calculation of the heat transmission based on the measurement results revealed a certain tendency in the relation between the external temperature and the remaining hours of the ice.We placed polystirene foam containers containing Japanese radiches in the thermostatic chambers at the temperatures of 5,15 and 25ﾟC and investigated the relation between the quantity of ice, the temperature declines of the Japanese radishes and the … More air in the boxes, the thermal capacity of Japanese radishes and the thermal insulation of the polystirene foam. The analysis of the results shows that the calculated values and the measured values roughly agree each other.We put eggplants, spinach, cucumbers and Chinese cabbages into polystirene foam containers, set some ice on and below the vegetables and analyzed the relation between the external temperature and the positions of the ice and the freshness of vegetables. The results reveal the fact that the temperature of the vegetables changes according to the position of the ice and that the cooling rate of the vegetables differs according to the position of the ice and according to the external temperature.While focusing on hydrocooling, we also examined air cooling, vacuum cooling and no-cooling for the freshness of Japanese radishes, broccoli and spinach.Japanese radish had the least weight loss. Thus, hydrocooling was the most suitable for it. Broccoli stored with hydrocooling had little weight loss but great change of color. Broccoli stored with vacuum cooling had great weight loss and little change of color. As for spinach, it showed the best performance with little weight loss in hydrocooling. Less