HOW EFFECTIVE IS ULTRASOUND ON BIOACTIVE COMPOUNDS EXTRACTION FROM GREEN PROPOLIS AND ITS BOTANICAL SOURCE?

Green propolis and its botanical main source alecrim-do-campo (Baccharis dracunculifolia) have considerable levels of bioactive compounds, which may be used in the food industry as a natural antioxidant. Despite the inefficient contribution of compounds released by some methods, the ultrasound assisted extraction has been used to cause cell collapse according to its cavitation forces, releasing the trapped compounds. The aim of this work was to verify how ultrasound assisted extraction influences the recovery of bioactive compounds from green propolis and Baccharis dracunculifolia buds. An experimental CCDR design was performed to optimize the extraction of bioactive compounds from alecrim-do-campo and the results were compared to previously established green propolis optimization data. The variables used were time (80 - 160 minutes) and ethanol concentration (0 - 99% ethanol/distillated water). Dependent variables were performed by in vitro tests of antioxidant capacity (FRAP, ABTS, DPPH) and total phenolic content (TPC). The results indicated that ultrasound was efficient in antioxidants extraction from alecrim-do-campo, just as it was for green propolis. In the case of alecrim, the optimized extract was obtained by using 99% of ethanol at 120 minutes. At this extraction conditions antioxidant capacity determined by FRAP was 534.3 µM Ferrous Sulfate / g sample, ABTS was 183.2 µmol TEAC / g sample, DPPH was 71.5 µmol TEAC / g sample and TPC was 53.2 mg GAE / g sample. Comparing the results, green propolis presented higher antioxidant capacity than its own source. Even so, it could be observed that, within the ranges of extraction variables studied, it was possible to obtain an optimized extract of alecrim-do-campo with considerable antioxidant capacity. This means that, although the method was efficient for both raw materials, it should be noted that green propolis has concentrated antioxidant compounds compared to this botanical source.