The aim of this work was to investigate the effect of freezing and long-term frozen storage on total phenolic, total anthocyanin contents and antioxidant activity of highbush blueberries (Vaccinium corymbosum L.). In addition, a HPLC method was developed for the determination of individual anthocyanins and chlorogenic acid contents. Blueberries were frozen at –18°C and –35°C and were stored at these temperature conditions for six months. Derivatives of malvidin and delphinidin accounted for 61% and 22% of total anthocyanin contents in fruit, respectively. Measurements of the antioxidant activity and bioactive compounds contents of blueberries showed there were no significant differences between fresh and frozen fruits. Also, at the end of frozen storage period, antioxidant activity remained significantly unchanged compared with the values measured just after the freezing process.

75-82