高压脉冲电场预处理对土豆真空冷冻干燥的影响

研究高压脉冲电场预处理工艺,可实现对果蔬细胞的可逆击穿,提高果蔬脱水速率,有望解决果蔬真空冷冻干燥过程中能耗大,时间长,加工成本高等实际问题。为此,选用土豆为试验材料研究高压脉冲电场预处理对真空冷冻干燥过程的影响。结果表明,高压脉冲电场预处理可以明显的提高土豆的干燥速率。通过极差分析得到电场参数的显著性程度依次为脉冲个数,脉冲强度和作用时间,最优工艺参数组合为:脉冲强度1500 V.cm-1、作用时间120μs、脉冲个数45个,与未处理相比,单位水分能耗降低了11.43%,干燥时间缩短了31.47%,单位面积生产率提高了32.28%。

Effect of High Pulsed Electrical Field Pretreatment on Vacuum Freeze-drying of Potato

High pulsed electrical field pretreatment on fruits and vegetables could enable the cell to break down,and increase drying rate.It is hopeful to solve practical problems in the vacuum freeze drying,such as energy consumption,high production costs and long drying time etc.The drying experiments were conducted to investigate the effect of high pulsed electrical field pretreatment of potato on the vacuum freeze drying.The results showed that high pulsed electrical field pretreatment could increase the drying rate obviously.According to the range analysis,the most important physical factors of high pulsed electrical field which affected the vacuum freeze drying were the pulse number,strength and duration.The optimal parameters of high pulsed electrical field for drying were obtained as follows: pulse strength 1500 V·cm-1,pulse duration 120μs,and pulse number 45.By using the above optimal conditions,energy consumption per unit of water was reduced by 11.43%,freeze drying time was shortened by 33.22%,and productivity per unit area was increased by 32.28% than results of the untreated group.