Chemical profile and antioxidant capacity of dried calyx of Colombian roselle (Hibiscus sabdariffa L.)

Calyx of Hibiscus sabdariffa L. has become as an excellent value added products for commercial exploitation during recent years in Colombia. The chemical characterization of H. sabdariffa calyx (Sudan cul tivar) growing in Colombia was carried out by measuring Total Phenolic Content (TPC), Total Flavonoid Content (TFC), Total Anthocyanin Content (TAC) and by LC-DAD-UV and LC-ESI-MS profiles. Furthermore, in vitro antioxidant properties (DPPH^• and ABTS^•+ radical scavenging abil ity and reducing power) were evaluated. Solvent extraction and extraction time were firstly optimized in order to ensure the best phenol-related compounds extraction. Analyzed samples exhibited variation for TPC (15.6-21.8 mg gallic acid equivalent/g dried sample), TFC (2.7-3.3 mg quercetin equivalent/g dried sample), and TAC (1.6-5.4 mg cyaniding 3-O-glycoside/g dried sample) values. DPPH^• and ABTS^•+ radical scavenging assays were correlated with TPC. Statistically significant differences (p≤0.05) for TPC, TFC, TAC, and antioxidant capacity assays were determined. The results suggested a growing place-dependent variation of the chemical profiles. These results could serve as a guide in the selection of Sudan cultivars of Roselle prior to their use in food industry and fresh market.