Antioxidant Activity and Phenolic Composition of Brazilian Honeys and their Extracts

The antioxidant activities and total polyphenolic content of five multifloral and four orange blossom Brazilian honey samples and their phenolic extracts were investigated. Identification and quantification of phenolic compounds were carried out by HPLC-DAD (high-performance liquid chromatography with diode-array detection). The radical scavenging activities, determined with 2,2-diphenyl-1-picrylhydrazyl (DPPH.) and expressed as EC50, ranged from 10.81 to 52.64 mg mL(-1) for honey and 6.17 to 52.87 mg mL(-1) for the extracts. The extract antioxidant activities were also determined by 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and ferric reducing antioxidant power (FRAP) assays, and the results varied from 46.53 to 383.49 mmol TE 100 g(-1) and 34.99 to 408.14 mol Fe(II) 100 g(-1), respectively. It was also evaluated the total phenolic and flavonoid contents by the Folin-Denis and aluminum chloride methods, respectively. Antioxidant activities and total phenolic contents were found to be highly correlated.