Factors that influence the yield and composition of Brazilian propolis extracts

During the extraction of propolis several factors were varied in order to determine how they affected the yield and phenolic composition of the obtained extracts. Six samples of green propolis from the Southeastern region of Brazil were tested. The results indicate that the highest yield of propolis extracts obtained by maceration, which also had the greatest number of components, were those using 70% (v/v) ethanol or more as a solvent. The Soxhlet extraction procedure resulted in even higher yields. No differences were observed between extracts macerated in the presence or absence of light. An increase in yield was observed between extracts macerated for 10 and 30 days although the phenolic content did not vary significantly. The total phenolic content of all extracts varied from 6.41 to 15.24 % but no direct correlation could be found between any of the factors tested.