title: Different extraction methods of biologically active components from propolis: a preliminary study.
abstract: BACKGROUND
  Propolis is widely used in apitherapy, preparations, and food and beverage additives. Various extraction techniques were applied in the extraction of the biologically active constituents of poplar type propolis in order to compare their efficiency. The methods employed were: traditional maceration extraction, ultrasound extraction (UE), and microwave assisted extraction (MAE).
  
  
  RESULTS
  The total amounts of extracted phenolics and flavonoids were determined, and the effectiveness of the methods compared. MAE was very rapid but led to the extraction of a large amount of non-phenolic and non-flavonoid material. UE gave the highest percentage of extracted phenolics.
  
  
  CONCLUSIONS
  Compared to the maceration extraction, MAE and UE methods provided high extraction yield, requiring short timeframes and less labour. UE was shown to be the most efficient method based on yield, extraction time and selectivity.
authors: Institute of Organic Chemistry with the Centre of Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria. bobi_tru@orgchm.bas.bg
authors: Boryana
authors: B
authors: Trusheva
authors: Dorina
authors: D
authors: Trunkova
authors: Vassya
authors: V
authors: Bankova