Obtaining Colombian propolis extracts using modern methods: A determination of its antioxidant capacity and the identification of its bioactive compounds

Abstract

In order to determine the most efficient method to extract bioactive compounds from Colombian propolis, a comparison was made between Soxhlet extraction (SE) and modern extraction methods. A higher yield was obtained by SE (76.55%), followed by microwave-assisted extraction (MAE) (73.84%), and finally extraction by supercritical CO2 fluid (SCCO2E) (1.32%). The highest amount of total polyphenols expressed as mg of gallic acid equivalent per gram of propolis (mg GAE)/gP) was obtained with the use of MAE (81.78), followed by SE (80.19) and SCCO2E (68.99). The highest flavonoid content expressed in mg of quercetin equivalents per gram of propolis (mg QE/gP) (60.11), was obtained using SCCO2E and 15% ethanol as adjuvant. The antioxidant capacity was higher for the extracts obtained with SCCO2E followed by MAE and SE. Finally, by means of HPLC-DAD, the bioactive flavonoids in the extracts obtained by supercritical CO2 were identified.