Optimization and comparative study of different extraction methods of biologically active components of Indonesian propolis Trigona spp.

Abstract

Application of propolis as a medicinal agent is not usually in the form raw material, but it must be purified by extraction with solvents. This extraction process should remove the inert material and preserve the polyphenolic (flavonoid and other phenolic compounds) fraction, which is considered to contribute more to the observed healing effects than the other propolis constituents. Aim of present study was to compare three methods of extraction: maceration, reflux, and microwave-assisted extraction (MAE), to extract polyphenolic fraction from Indonesian propolis Trigona spp. All of the methods were carried out in optimal conditions. Response surface methodology (RSM) was used to optimize the parameters of extraction such as extraction time, the concentration of solvent (ethanol), and microwave power. Total phenolic and flavonoid contents were determined by spectrophotometric method. The results showed that the relationship between the response (flavonoid and total phenolic yields) and the parameters of extraction followed significantly a second order polynomial models (P<0.05). Under optimal conditions, the method of maceration and reflux gave a similar yield, ie about 0.2% and 4% of flavonoid and total phenolic, respectively. The increase of yield was observed in MAE method that was 0.4% and 5.8% of flavonoids and total phenolics, respectively. On the basis of yield, extraction time and solvent consumption, MAE method was more efficient and selective in extracting flavonoid and total phenolic than those of two other methods.