Preharvest β-aminobutyric acid treatment alleviates postharvest deterioration of Bluecrop highbush blueberry fruit during refrigerated storage

Abstract

We examined the effect of preharvest beta-aminobutyric acid (BABA) treatment on postharvest quality and the softening of 'Bluecrop' highbush blueberry fruit during postharvest refrigerated storage. Reddish purple-colored fruit on shrubs were treated with 20 mM BABA and harvested 7 days after treatment when they turned dark purple. The harvested fruit were stored in clear polyethylene terephthalate clamshells at 2 degrees C for up to 20 days. Preharvest BABA treatment significantly delayed color changes, enhanced individual soluble sugars and organic acids, and reduced decay incidence. BABA-treated fruit also retained higher skin firmness throughout the storage period. Cell wall materials, closely associated with fruit softening, were significantly higher in BABA-treated fruit than in control. Moreover, preharvest BABA treatment significantly enhanced fruit pectin content at harvest and reduced activities of polygalacturonase and endo-1,4-beta-xylanase, although hemicellulose content was unchanged. These results suggest that preharvest BABA treatment alleviates the deterioration of postharvest quality in 'Bluecrop' highbush blueberry fruit including skin firmness during refrigerated storage.