Phenolic acids in the inflorescences of different varieties of buckwheat and their antioxidant activity

The comparative analysis of total phenolics and phenolic acid composition together with parameters of antioxidant activities was studied in the inflorescences of three varieties of buckwheat (F. esculentum, Fagopyrum tataricum rotundatum and Fagopyrum esculentum, forma green-flowers). Antioxidant activity of extracts of these buckwheat varieties has been found high and at the same time extracts of inflorescences of green flower buckwheat have been characterized by the highest total phenolic content. Eight phenolic acids (ferulic acid, vanillic acid, chlorogenic acid, p-coumaric acid, trans-ferulic acid, p-anisic acid, salicylic acid and methoxycinnamic acid) were found in the investigated buckwheat inflorescences with HPLC analysis. Inflorescences of F. esculentum, forma green-flowers have a high content of chlorogenic acid (16 mg 100 g−1 DW) and p-anisic acid (872 mg 100 g−1 DW). The highest content among the investigated buckwheat inflorescences of vanillic acid, trans-ferulic acid, chlorogenic acid and p-anisic acid was found in the F. tataricum, F. esculentum inflorescences have been characterized by the highest content of salicylic acid (115 mg 100 g−1 DW) and methoxycinnamic acid (74 mg 100 g−1 DW).