Electrode configuration and polarity effects on physicochemical properties of electric field treated apples post harvest

The trial compared the use of needle and plate electrode configuration (corona discharge) with parallel plate electrode configuration for postharvest treatment of apples (Malus domestica Borkh, cv. Fuji and Golden Delicious) during storage. The effect of electric field direction on physicochemical properties of fruit was also investigated. In Fuji apple storage, physicochemical parameters varied with water core content. Treatment of apples kept between parallel plate electric field suppressed weight loss unlike in the corona discharge field. Respiration and climacteric peak were suppressed in apples kept between parallel plate electric field. In corona discharge, after 7 days more respiration was noted in the treated than the untreated samples. The 'reversed' electric field treatment (apples on cathode plate) gave higher weight loss than the corresponding 'forward' electric field treatment (apples on anode plate) in the parallel plate arrangement. In corona discharge, the multiple of evaporation rate (ratio of water loss in treated sample to that of untreated sample) was higher for the 'forward' electric field direction (negative needle polarity) than the 'reversed' electric field direction (positive needle polarity). (C) 2003 Silsoe Research Institute. All rights reserved Published by Elsevier Ltd.