Direct Current Electrical Field Effects on Intact Plant Organs

Intact plant tissues (of hypocotyls, radicles, cotyledons and leaves) were contracted by applying a low DC electrical field through them. Stomatal opening as a result of the electrical treatment of leaves was observed, presumably due to the differential influence of the electrical treatment on guard cell turgor pressure versus turgor pressure of the surrounding epidermal cells. In addition, leakage of minerals from the treated leaves was detected (higher contents of potassium, sodium, calcium and sulfur), as was leakage of betanin from electrically treated red beet roots (higher OD value of the immersion solution with increasing time of applied electrical field). Application of such a treatment can be used for initial drying or as part of another more drastic drying method. The advantages of this method lie in its nonthermal character and its potential to increase the quality of processed foods by maintaining their “like-fresh” quality, e.g., fruits and vegetables that are less damaged by browning. An understanding of the mechanism involved in this nonthermal application can help in controlling the process and predicting its outcome.