高压矩形脉冲电场对果蔬干燥速率的影响

The Effect of Rectangular High-pulsed Electric Field on Drying Rate of Fruits and Vegetables

高压矩形脉冲电场作用果蔬后能有效地击穿细胞膜,增强渗透性,最大限度地提高干燥速率,缩短加工时间,减少加工能耗。为此,在高压矩形脉冲电场下对萝卜进行干燥前预处理,运用响应面设计法进行对比试验,分析了萝卜干燥速率的变化,获得了高压矩形脉冲电场预处理的优化工艺参数。结果表明:高压脉冲电场的3个参数对白萝卜干燥性能的影响均达到极显著水平,作用程度依次为脉冲强度、脉冲个数和作用时间;经高压脉冲电场预处理后干燥速率比未处理的平均提高13%,当脉冲强度、脉冲个数和作用时间为1420V/cm,30个,110μs时预处理效果最佳,干燥速率比未处理提高40%。结果表明,采用高压脉冲电场预处理对提高果蔬干燥速率效果明显,作为预处理工艺应用于加工时间长、能耗大的真空冷冻干燥中有很好的应用前景。

Membrane could be effectively punctured and osmosis of cell was enhanced after Rectangular High-pulsed Electric Field （RHPEF） processing the fruits and vegetables,thus furthest increasing drying rate,shortening processing time and reducing processing energy.In this study,RHPEF was used to pretreat radish before drying,response surface design was applied for contrast test and drying rate change of radish was analysed,thus obtaining the optimal technological parameters of RHPEF pretreatment. The results showed that the influence of three parameters of RHPEF on radish drying performance reached significant level,and impact extent was in the order of pulse intensity,pulse number and action time. Drying rate of pretreated radish was 13% higher on average than that of untreated one,and 40% higher when pretreatment effect was best if pulse intensity was 1420V/cm,pulse number was 30 and action time was 110μs.The results showed that the effect of RHPEF pretreatment was obvious to increase the drying rate of fruits and vegetables and the pretreatment process was of good application prospect in vacuum freeze drying of longer processing time and large expenditure of energy.