Impacts of organic and organo-mineral fertilizers on total phenolic, flavonoid, anthocyanin and antiradical activity of Okuzgozu (Vitis vinifera L.) grapes

A present study was conducted to determine the impacts of organic and organo-mineral fertilizers on total phenolic, flavonoid, anthocyanin and antiradical activities of Okuzgozu (Vitis vinifera L. cv.) grapes. Study treatments included organic fertilizers (green fertilizer (vetch), green fertilizer (barley), green fertilizer (vetch + barley), farmyard manure, bactoguard, lifebac NP, humanica) and organo-mineral fertilizers (bactolife quality organo, bactolife high organo, bactolife high organo, bactolife super organo power). The control treatment did not receive any application. The organic, and organo-mineral fertilizers applications positively influenced the total phenolic, flavonoid and anthocyanin productions, and antiradical activity (DPPH). The maximum total phenolic production was significantly higher under Bactolife Super Organo Power (785.49 µg GAE/mg in pulp) application, followed by those under bactolife high organo 5-5-5 (780.40 µg GAE/mg in pulp). The total flavonoid production in berry skin (34.26 µg QUE/mg), pulp (137.00 µg QUE/mg) and seed (23.52 µg QUE/mg) were the highest under the bactolife super organo power whereas the antiradical activities (DPPH) of berry pulp and seed were at the maximum level under the bactolife quality organo treatment. Total anthocyanin content of berry skin and pulp of Okuzgozu grape cultivar was the highest under the organic humanica.