Harvest date and storage effect on fruit size, phenolic content and antioxidant capacity of wild blueberries of NW Ontario, Canada.

Abstract

Blueberries are eaten fresh or after storing at room temperature, refrigerator or freezer but little is known about changes in food values of wild blueberries due to harvest dates and storage conditions. The aim of this study was to investigate the effect of harvest date and storage conditions of wild blueberries on berry quality and health related chemistry. We analyzed Vaccinium angustifolium, V. angustifolium var. nigrum, and V. myrtilloides native to NW Ontario, Canada harvested early and late in the season for total phenol (TP), anthocyanin contents (AC), and soluble solids to titratable acidity ratio storing at room temperature, refrigerator and freezer temperature. We also determined their antioxidant content and activity (ORAC). Late harvest and low temperature storage significantly increased TP and AC for most genotypes. In V. myrtilloides TP increased by 50, 44 and 45% respectively at late harvest, 14days refrigerator and 90days freezer storage. It also had significantly higher ORAC (22 and 33%) than the other two genotypes. Wild blueberry pickers and consumers can optimize health benefits and quality attributes of blueberries by customizing harvest protocols and choice of cultivar and storage in household fridge and freezer. Blueberry storage, at household fridge and freezer temperature, does not reduce its health benefits.