Blueberries (Vaccinium spp.) may be considered one of the best potential sources of antioxidants in the
diet. This characteristic results from the presence of flavonoids (especially anthocyanins), tannins and
phenolic acids in the fruits. The objective of this work was to analyze the anthocyanin stability and
antioxidant activity of refrigerated whole blueberry juice stored at 4 8C for 10 d, and of fruits stored
frozen (18 8C) for 6 months, in order to determine the changes occurring during storage. The frozen
fruits showed a significant increase (p < 0.05) in antioxidant activity during the 3rd month of frozen
storage, followed by a decrease up to the end of the 6-month period. The juice was analyzed every other
day, and the antioxidant activity changed on the 8th d of refrigerated storage, remaining stable up to the
10th d. There were significant losses of anthocyanins both in the frozen fruits (59%) and refrigerated juice
(83%). The antioxidant capacity was shown to be stable during cold storage both in the case of the fruits
and whole juice, whereas the anthocyanins were degraded, possibly due to oxidations and/or
condensation reactions with other phenolic compounds. More studies are required to optimize the
storage time and temperature of these products with respect to nutrient stability.