高压脉冲电场对果蔬生物力学性质的影响

高压脉冲电场预处理果蔬，使其组织细胞在产生可逆击穿下，进行真空冷冻干燥加工，可大大地提高脱水速率和降低冻干能耗。但认识其作用机理和优化工艺参数，需要进一步研究高压脉冲电场对果蔬材料生物力学性质的影响。该文研究了高压脉冲电场处理胡萝卜、白萝卜和苹果对其生物力学性质的影响，通过测定其剪切强度、弹性模量、材料硬度值和压缩屈服极限，并与对照组进行比较，结果表明预处理后材料的剪切强度、弹性模量及屈服极限均比对照组降低，胡萝卜的硬度值比对照组降低，而白萝卜和苹果的硬度值则高于对照组。运用SAS软件对试验数据进行多元回归分析获得了高压脉冲电场预处理果蔬的工艺参数以及相关寻优模型，为高压脉冲电场预处理工艺的确定提供参考。

Effect of high pulsed electric field on biomechanical properties of fruits and vegetables

In order to study the pre-processing of fruits and vegetables attacked by high pulsed electric field (HPEF) to a degree that the tissue cells are broken down reversibly, it is needed to further study the effects of the HPEF processing parameters on the biomechanical properties of fruits and vegetables in relative to the vacuum freeze-drying rate and energy consumption. The influential mechanism of HPEF on the biomechanical properties of carrots, white radishes and apples was investigated. Shear strength, elastic moduli, firmness and compression yield strength were selected as the material properties to evaluate effects of HPEF treatment. Test results showed that: the shear strength, compression yield strength and elastic moduli of the materials were lower than those of the control groups; the firmness of carrots was lower, while the firmness of the white radishes and apples was higher than that of the control groups. According to the multiple regression analysis with SAS software, the processing parameters of HPEF were determined and mathematical model was estabished, which provided technical supports for vacuum freeze-drying practice.