Cell wall and reactive oxygen metabolism responses of strawberry fruit during storage to low voltage electrostatic field treatment

Abstract

Low voltage electrostatic field (LVEF) is a new, non-thermal and low-cost fresh-keeping technology. However, there are few studies to evaluate the effects of LVEF on cell wall metabolism and reactive oxygen metabolism of strawberries. In this investigation, strawberries were stored in LVEF at 4 ± 1 °C for 10 d to explore the mechanism of cell wall metabolism and the effect of reactive oxygen on fruit quality. After 10 d of storage, strawberries were of better qualities compared to control group, with fruit firmness increased by 17 %, decay incidence decreased by 38%, weight loss reduced by 25 % and relative conductivity reduced by 38 %. Meanwhile, LVEF treatment significantly inhibited the accumulation of malondialdehyde, hydrogen peroxide and superoxide anion, and induced an increase of superoxide dismutase, catalase and ascorbate peroxidase activities. LVEF treatment also retained antioxidant components such as ascorbic acid and reduced glutathione. In addition, LVEF treatment slowed down the degradation of protopectin to water-soluble pectin and inhibited the activities of cellular degradation enzymes, including pectin methylesterase, polygalacturonase, cellulase, β-xylosidase and Xyloglucan endotransglycosylase/hydrolase. These results demonstrated that LVEF treatment might be an effective method for extending strawberries shelf life.