Prior et al. (1998) report the contribution by ascorbate
to the antioxidant capacity of highbush blueberries as
2.3% and for lowbush blueberries as 1.5%; this is
compared to values in the present study of 0.8% and
0.6% for these fruits, respectively. The difference is due
to lower ORAC values determined by Prior et al. (1998).
The fact that losses in ascorbate did not affect the
antioxidant capacity of lowbush blueberries or raspberries
is consistent with the observation that ascorbate
does not contribute greatly to the antioxidant capacity
of fruits.
In conclusion, this study compares and confirms the
work of Wang et al. (1996) and Prior et al. (1998) in
that blueberries have a high antioxidant capacity
compared to strawberries and other fruit such as
raspberries. The small contribution of ascorbate to the
total antioxidant capacity of fruit is also confirmed in
the present results. New information is presented on
the effect of storage practices on fruit chemistry and
antioxidant capacity which suggests that storage at
ambient or above ambient temperatures will positively
affect phenolic metabolism to enhance the antioxidant
capacity, and therefore the health functionality of some fruit crops. Although storage practices that were identified
to be beneficial may not be commercially practical,
other treatments which similarly stimulate phenolic
production (e.g., UV irradiation, ozonation) may be
explored for commercial storage with the aim of improving
the health quality of fruit.