Abstract: A total of 42 samples were collected from honey samples of 5 different unifloral origins (each unifloral origin consisted of different geographic origins in China). Phenolic extract was obtained from these selected samples using Amberlite XAD-2 absorption resin. The contents of total phenolic acids and total flavonoids were spectrometrically determined, and reducing power and the scavenging activity against DPPH and superoxide anion free radicals were tested to evaluate the effects of floral origin, sample color and geographic origin on the antioxidant activity of honey. Total flavonoids content ranged from (9.41 ± 0.18) to (92.76 ± 0.13) mg/kg as determined using quercetin as the reference standard. The content of phenolic compounds ranged from (9.10 ± 0.05) to (149.57 ± 0.14) mg/100 g as determined using protocatechuic acid as the reference standard. Dark honey had the highest scavenging activity on DPPH and superoxide anion free radicals with EC50 of (0.042 ± 0.014) g/mL and (0.038 ± 0.009)g/mL, respectively. Conclusion: phenolic extracts from honey samples have impact on their antioxidant activity. The antioxidant potential is positively correlated with the contents of phenolic or flavonoid compounds. Dark honey has higher contents of phenolic and flavonoid compounds as well as stronger antioxidant potential than other light honey.

Key words: unifloral honey, phenolic extract, antioxidant activity, color, geographic regions