Fruits of different Sorbus L. species have been traditionally used in food production and in the treatment of various ailments. Besides common antioxidant active phytochemicals such as ascorbic acid, tocopherols and carotenoids, fruits are rich in phenolic compounds that are of particular interest. In this study, profiles of separate antioxidant active compounds (reducing and radical-scavenging activities) were investigated using online assays with post-column reactions. Significant variations in phenolic acids and flavonoids contents and antioxidant activity values were observed in the fruits of Sorbus L. species studied. Neochlorogenic and chlorogenic acids were determined as markers of antioxidant activity. Characteristic patterns of antioxidant profiles obtained using HPLC post-column FRAP and ABTS assays significantly depend on specific Sorbus L. species and are suitable for equivalency research of Sorbus L. fruits.
Keywords: ABTS; FRAP; Sorbus L; antioxidant profile; phenolic compounds; post-column assay.