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.