Determination of Flavonoids in Pulp and Peel of Mandarin Fruits

The aim of this study was to determine total flavonoids and individually flavanon glycosides as well as antioxidant capacity in pulp and peel of two mandarin groups, namely Satsuma (Citrus unshiu Marcovitch) cv. Saigon and Clementine (Citrus reticulate var. clementine) cv. Corsica SRA 63. Total flavonoids content was measured using colorimetric method, whereas HPLC-PDA detection was used for the analysis of individual flavanone glycosides (narirutin, naringin and hesperidin). In addition FRAP method was used to determine the antioxidant capacity. The results of colorimetric method showed that there was high concentration of flavonoids in all investigated samples, especially in peels (1156 mg/100 g in Satsuma peel and 804 mg/100 g in Clementine peel). Among the flavonone glycosides, hesperidin, was determined in the highest concentration in both investigated pulps. In peels flavanon glycosides were present in decreasing sequence as follow: narirutin>hesperidin>naringin. According to FRAP method, all samples possess an evident antioxidant capacity especially peels. Correlation between total flavonoids, hesperidin, naringin, narirutin and antioxidant capacity was very high with correlation coefficiants between 0.81 and 0.98