Durante a extração de própolis foram variados alguns fatores para determinar como eles afetam o rendimento e o teor de fenóis totais. Seis amostras diferentes da região sudeste do Brasil foram testadas. Os resultados indicam que os maiores rendimentos de extratos de própolis obtidos por maceração, que também apresentam o maior número de componentes, foram aqueles usando 70% (v/v) ou maior proporção de etanol no solvente. A extração em Soxhlet resultou em um maior rendimento. Não foram observadas diferenças entre extratos de macerações com ou sem luz. Um aumento no rendimento da extração foi observado entre os extratos obtidos por maceração durante 10 e 30 dias, porém o teor de fenóis não variou significativamente nesses extratos. O teor de fenóis totais de todos os extratos variou entre 6,41 e 15,24% mas nenhuma correlação direta foi encontrada com qualquer um dos fatores testados.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.
Keywords: propolis, extraction techniques, high performance liquid chromatography
IntroductionPropolis, a resinous substance collected by bees from plants around the hive, is masticated by the bees, salivary enzymes and beeswax added, then applied to the combs and walls of the hive, 1 thereby insulating and reinforcing the hives as well as making the environment aseptic. For beekeepers, propolis is a by-product obtained by scraping the walls of the hives. Crude propolis is composed basically of 55% vegetable resins and balsam, 30% bee wax, 10% essential oil and 5% pollen. 2 Due to its antibiotic and anti-fungal activity, propolis has been used in folk medicine for many centuries 3 and is presently used in health food and various pharmaceutical and cosmetic products such as mouthwash preparations, face creams, lotions and tablets. 1 Traditionally, the fraction soluble in 70% ethanol was extracted and referred to as propolis balsam. 3 In order to avoid the characteristic ethanolic smell and solubility problems of this product, propolis extracts using water 4 or other solvents such as glycerol, edible oils and propylene glycol 5 are presently found on the market. There is no standard either for extractive procedure or composition of products that contain propolis extracts...