Variation of Polyphenol Content and Antioxidant Activity in Some Bilberry (Vaccinium myrtillus L.) Populations from Romania

Fruits of bilberry (Vaccinium myrtillus L.) are valued mainly for their nutraceutical properties, and are among the fruits with the highest antioxidant activity due to their high content of phenolic compounds. The aim of this research was to assess the total polyphenol content and antioxidant activity of fruits in six wild bilberry populations from two regions of Romania over three years. The total polyphenol content was determined according to the Folin–Ciocalteu modified method, while the antioxidant activity was evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging assay. The Padis and Raul Lung populations registered the highest values of polyphenol content and antioxidant activity, as such the fruits of these bilberry populations could be considered potential sources of antioxidants for direct consumption or for use as ingredients for food products or food supplements. Significant variation of total polyphenol content and antioxidant activity was observed both between populations from the same region and from different regions. The low level of broad sense heritability for total polyphenol content and antioxidant activity associated with the high effects of year, and population–year interaction indicates that the accumulation of polyphenols in bilberry fruits is influenced by changes in environmental conditions.