Total phenols and antioxidant activities of natural honeys and propolis collected from different geographical regions of Ethiopia
In this study, ten honey and five propolis samples from different geographical origins were tested. Both honey and propolis samples showed high content of total phenolic compounds (330-610 mg gallic acid equivalent (GAE)/100 g honey; 365-1022 mg GAE/g ethanol extract of propolis (EEP). The total flavonoids ranged from (15.1-42.6 mg catechin equivalent (CE)/100 g for honey; to 123-74 mg CE/g for EEP. These honeybee products of Ethiopia had high total radical scavenging properties with respect to 2,2-diphenyl-1-picryl-hydrazyl (DPPH); 18.1-59.8% and 48.6-87.8% for honey and EEP respectively. Furthermore, the hydroxymethylfurfural (HMF) of the honey samples was found to be low with a mean value of 4.8 mg/kg suggesting that the samples were of good quality. The antioxidant properties of the products showed a good correlation (r2 = 0.50-0.82) with their polyphenolic contents.
KEY WORDS: Ethiopia, Honey, Propolis, Polyphenols, Flavonoids, Antioxidants
Bull. Chem. Soc. Ethiop. 2015, 29(2), 163-172