Antioxidant Activity and Total Phenolic Content of Stingless Bee Propolis from Indonesia

The aim of this study was to investigate antioxidant activity, total phenolic compounds and flavonoids of propolis from three provinces of Indonesia with two methods of extraction. Stingless bee propolis from Banten, South Kalimantan, and South Sulawesi was prepared through ultrasound-assisted extraction with water and ethanol solvents, separately. Antioxidant activity was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolic and flavonoid contents were analyzed by Folin-Ciocalteu colorimetric and aluminum chloride (AlCl₃) methods, respectively. The result showed that the antioxidant activity expressed as IC₅₀ of Indonesian propolis ranged from 452.52 to 1027.29 mg/L. Ethanol extracts showed higher antioxidant activity than water extracts. Total phenolic and flavonoids content detected in the samples ranged from 10.00 to 28.65 mg/g GAE and 0.76 to 3.39 mg/g QE, respectively. The ethanol extract of propolis from South Kalimantan had the highest total phenolic contents, while that from South Sulawesi possessed the highest total flavonoids.