蔬菜真空冷却工艺的实验研究

真空冷却是一种能提高果蔬贮藏品质并可延长货期的快速预冷方法。本文以卷心菜、大葱、豆角和韭菜为研究对象,利用BSVC5真空预冷机,针对加水、包装、降压和复压等工序进行实验研究。结果表明,真空冷却前对蔬菜加水和包装能够明显加快冷却速度和降低失重率,且加水量应低于6%;采用分阶段降压能使蔬菜降温更均匀,并根据蔬菜自身性质终压应控制在200～750 Pa范围内,采取引入冷空气复压的方法可以避免蔬菜温度回升。

Experimental studies on vacuum cooling technology of vegetable

Vacuum cooling has been used as a rapid cooling method for vegetable and fruit to enhance their quality and shelf life.The craft and parameters of vacuum cooling are studied by experiment in BSVC5 vacuum cooling equipment,for cabbage,scallion,beanstalk and leek.The results show that humidifying and packaging could significantly enhance the cooling rate and decrease the mass loss,while the percent mass of humidifying is below 6%.The multi-stage vacuum pressure reserving process could make the temperature distribution of vegetable to be more uniform,while the cooling pressure ought to be between 200 Pa and 750 Pa.It is discovered that the temperature rise of the cooled vegetable could be effectively relieved by inducting the cooled air into the vacuum chamber during the pressure-restoring process.