Abstract: Blueberries are widely valued for their high content in
phenolic compounds with antioxidant activity, and hence beneficial
for the human health. In this way, a study was done to determine the
phenolic composition (total phenols, anthocyanins and tannins) and
antioxidant activity of blueberries from three cultivars (Duke,
Bluecrop, and Ozarkblue) grown in two different Portuguese farms.
Initially two successive extractions were done with methanol
followed by two extractions with aqueous acetone solutions. These
extracts obtained were then used to evaluate the amount of phenolic
compounds and the antioxidant activity. The total phenols were
observed to vary from 4.9 to 8.2 mg GAE/g fresh weight, with
anthocyanin’s contents in the range 1.5-2.8 mg EMv3G/g and tannins
contents in the range 1.5- 3.8 mg/g. The results for antioxidant
activity ranged from 9.3 to 23.2 molTE/g and from 24.7 to 53.4molTE/g, when measured, respectively, by DPPH and ABTS
methods. In conclusion it was observed that, in general, the cultivar
had a visible effect on the phenols present, and furthermore, the
geographical origin showed relevance either in the phenols contents
or the antioxidant activity.