基于电镜观察及介质理论分析高压脉冲电场处理果蔬机理

通过对苹果和白萝卜进行高压脉冲电场(HPEF)预处理及超微结构电镜试验,研究HPEF预处理脉冲强度、脉冲宽度和脉冲个数对果蔬细胞结构的作用机理。结果表明,HPEF预处理可改变果蔬细胞膜通透性,使果蔬细胞结构受到严重破坏。通过结合介质理论对其机理进行推导,得知高压脉冲电场处理果蔬的主要影响因素为电场强度。在电场作用下,果蔬组织内部的受力与电场强度的平方成正比,脉冲宽度和脉冲个数对电击穿也有一定的影响,为高压脉冲电场处理果蔬工艺参数的选择提供了理论依据。

MECHANISM OF HIGH-PULSED ELECTRIC FIELD PRETREATED FRUITS AND VEGETABLES BASED ON MEDIUM THEORY AND SCANNING ELECTRON MICROSCOPE OBSERVATION

The micro-structures of apple and radish samples after high-pulsed electric field (HPEF)pretreatment were studied by electron microscope experiments and the mechanism of the cell structure of apple and radish samples under HPEF pulse intensity, pulse length and pulse number were investigated. The results showed that the membrane permeability of apple and radish samples were changed and cell structure of them were heavily damaged by HPEF pretreatment. Derived form medium theory, it showed that the electric field intensity was the main factor of HPEF pretreatment. The force in sample tissue was proportional to the square of electric field intensity, and the pulse length and pulse number also had electric breakdown effects. These provides a theoretical basis of HPEF pretreatment parameters on fruits and vegetables.