Effects of acidic electrolyzed oxidizing water on retarding cell wall degradation and delaying softening of blueberries during postharvest storage

Abstract

This study was to evaluate the effect of acidic electrolyzed oxidizing water (AEW) on extending the shelf-life of blueberries during postharvest storage. On day 0, two cultivars of blueberries (Brightwell and Camellia) were washed by AEW with available chlorine concentration (ACC) of 48 mg/L at pH 2.8 for 5 min, and then stored at 4 °C until analyzing. Quality attributes of blueberries including firmness, cell wall composition and cell wall degrading enzymes were analyzed on days 0, 3, 6, 9, 12 and 15. Results showed that Brightwell softened faster than Camellia. AEW treatment slowed down the softening of both cultivars, while it had higher efficacy on delaying the softening of Camellia blueberries than the Brightwell blueberries. In addition, AEW treatment deactivated different cell wall degrading enzymes (CWDEs, polygalacturonase (PG), cellulase and β-galactosidase) and prevented the degradation of cell wall components including Na2CO3-soluble pectin (NSP), hemicellulose and cellulose. These results suggested that AEW treatment can be used as a postharvest technique to delay the softening process of blueberries during storage through lowering CWDEs activities and preventing degradation of cell wall components.