Effect of the maceration time on chemical composition of extracts of Brazilian propolis

Abstract

SummaryIt is believed that longer maceration times change significantly the ethanolic extract composition of propolis, improving its pharmacological, nutritional and antimicrobial properties. To probe whether such superior composition is indeed obtained, 10 samples of propolis from several regions in Brazil and one sample from North America were left to macerate in 70% ethanol for periods between 20 days and one year. The resultant extracts were evaluated in terms of the yield of extracted material and also analyzed by electrospray ionization mass spectrometry (ESI-MS) fingerprinting. A small increase in the yield of the extracted material over the period analyzed was observed. ESI-MS fingerprints indicate qualitatively the same composition but with a greater incidence of the high-mass components after six months. The extracts of one sample of green Brazilian propolis were also quantified using both gas chromatography mass spectrometry and high performance liquid chromatography. No new components were identified after longer maceration times and the changes in the relative concentrations of the identified components were in line with the results of the yield and ESI-MS fingerprints. Therefore, prolonged extraction periods do not necessarily result in richer propolis extracts.