预冷终压对蔬菜真空预冷失水率的影响

Effect of precooling final pressure on water lossr rate of vegetables in vacuum precooling

为研究真空预冷过程中预冷终压对蔬菜的影响,总结不同类型蔬菜的最佳预冷终压,取菠菜、娃娃菜、茄子为三类蔬菜代表,将其在不同预冷终压下进行预冷效果比对,并对各类蔬菜进行最佳预冷终压验证,确定最佳补水率及补水方式。结果表明,最佳预冷终压为:叶菜类800 Pa,含蜡质层类700 Pa,根茎及茄果类600 Pa。最佳补水率为:对应终压下的失水率,但不应超过自身重量的4%。对比直接预冷、直接补水、包覆膜补水,包覆膜补水效果最好。通过实验总结各类蔬菜不同预冷终压下的失水率并寻找最佳保护措施,可以有效降低真空预冷中蔬菜的质量损耗以及制冷系统能耗。

To study the effect of precooling pressure in vacuum precooling and summarize the optimal precooling final pressure of different vegetables, these vegetables of spinach, baby vegetable and eggplant were selected as three types of vegetables, and the precooling effects were compared under different precooled final pressures. Choosing different vegetables verified the optimal precooling final pressure. Determined the optimal water recharge rate and water recharge method. The results show the optimal precooling final pressure is 800 Pa for the leafy vegetables, 700 Pa for the waxes layer vegetables, and 600 Pa for the roots fruit tomato class. The optimal water recharge rate should be water loss rate under the corresponding final pressure. But it should not exceed 4% of its own weight. Compared with direct precooling, direct water replenishment, and coating replenishment, the effect of coating replenishment is best. Summarizing the water loss rate of various vegetables under different precooling final pressure, best protection measures can effectively reduce the food loss and the energy consumption of the refrigeration system in vacuum precooling.