Effects of Nanosecond Pulsed Electric Fields on Agricultural Product

——Cell Morphology of Grape Skin after High Electric Fields Treatment and Total Polyphenols of Transudate——

Abstract

Feasibility of applying a nanosecond band pulsed electric fields (nPEF) to agricultural process was considered. We developed a set of equipment for measurement : first was a nanosecond pulsed power generator whose pulse width was fixed at around 140ns ; second was a needle-to-plate electrode reactor. Grape skin was immersed in the electrode reactor filled with distilled water. It was treated with nPEF and the cell morphological changes were observed by using a microscopy. In addition, the total polyphenols in the transudate due to nPEF treatment was measured. Results showed that many anthocyanoplasts in cells were collapsed, and there was a remarkable increase in total polyphenols in the transudate under high voltage conditions. It was suggested that a decrease in pulses per second (pps) could treat the sample with less temperature rise.