Direct Current Electrical Field Effects on Intact Plant Organs

Abstract

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.

Pulsed electric field stimulates plant secondary metabolism in suspension cultures of Taxus chinensis*

“…In our work, the maximal field strength was 10 V/m, which was too low to cause electroporation; in addition, the ''permeability'' lasted for several days, because the maximal amount of extracellular Tc and phenolics was reached 3 days after PEF treatment, which was completely different from the transient response time for electroporation reported by Angersbach et al (2000). Ganeva et al (2002) and Zvitov et al (2003) also reported that application of electrical field to yeast or plant tissues led to leakage of intracellular substances to the surrounding medium. In addition, our experimental results show that the amount of extracellular Tc and phenolics decreased rapidly after day 3 (Table I).…”

A novel protecting method for visual green color in spinach puree treated by high intensity pulsed electric fields

“…When the electric field strength was higher than 70 kV/cm, the color value decreased slowly with the increased electric field strength. Direct current electric field can destroy the micro-structure of vegetable (Zvitov, Schwartz, Zamski, & Nussinovitch, 2003). Thus, the higher electric field strength may destroy the micro-structure which can protect chlorophyll which is not to be destroyed.…”

Betanin: A Red-Violet Pigment - Chemistry and Applications

“…[16,17]. To improve the betalain extraction, some of the pretreatment methods have been proposed, such as pulsed electric fields [18], gamma irradiation [8], and low-direct current electric fields [19]. But, such methods are quite expensive when compared to the solvent extraction techniques.…”