Phenolic compounds and vitamin C as sources of antioxidant activity in black currant fruit (Ribes nigrum L.)

Abstract

The content of some important phenolic compounds (kaempferol, myricetin, quercetin, and ellagic acid), total phenolics (TPH), vitamin C, and total antioxidant capacity (TAC) in the fruit of three black currant cultivars (Ben Lomond, Ben Sarek and Malling Juel) were studied. The content of individual phenolic compounds showed variability among the studied cultivars. The main flavonol found in cv. Malling Juel was kaempferol (1.60 μg g^-1 FW), whereas the lowest values of myricetin (5.46 μg g^-1 FW) and quercetin (7.65 μg g^-1 FW) were also observed in the fruit of this cultivar. Ellagic acid content was the highest in cv. Ben Lomond (12.90 μg g^-1 FW), which is also characterized by lower values of individual flavonols compared to other cultivars tested. However, the highest TPH level was recorded in cv. Ben Lomond (4.71 mg g^-1 FW).

Vitamin C content in fruit of cv. Malling Juel was at a very high level (141.4 mg 100 g^-1), whereas cv. Ben Lomond expressed the highest level of TAC (7.60 mg asc g^-1 FW). Overall, the content and profile of phenolic compounds in the black currant cultivars showed significant contribution to the expressed antioxidant capacity which was confirmed by positive correlation between TPH and TAC obtained in this study. Besides total phenolics, vitamin C is also a significant contributor to the measured antioxidant capacity in black currant fruit indicating that some cultivars with lower phenolic content may express high TAC.