Study on content and antioxidant activity of anthocyanins from different maturity of Northcountry bilberry fruits

To take full advantage of the bilberry resources and determine appropriate harvest time,four different maturity stage:green white period,powder ripe period,bright blue period,and mature late period of cultivated variety Northcountry bilberry were harvested respectively.Then the content and antioxidant activity of anthocyanins were studied and found that the ratio of sugar to acid could affect the content of anthocyanins.The results showed that the correlation between the content of anthocyanine and the ratio of sugar to acid were always positive,and the increase of sugar-acid ratio also promoted the formation of anthocyanins;with the maturity of the fruits,anthocyanins content increased gradually,and in bright blue period reached the highest 150.54mg in 100g fruit.The anthocyanin of all those four harvest times of Northcountry fruits had excellent antioxidant activities,and the anthocyanins content was positively correlated with the antioxidant activity.In Northcountry bilberry bright blue period,the antioxidant activity such as DPPH free radical-scavenging power assay,reducing power assay and their scavenging power assay on lipid peroxidation,·OH and O2-· were highest.The scavenging power assay on lipid peroxidation and ·OH of cultivated bilberry variety Northcountry fruits was higher than VC.