Comparison between maceration and ultrasound-assisted extraction of white bracts with flowers of Bougainvillea spectabilis Willd.

Obtaining bioactive compounds depends on the extraction method, with maceration being the most well-known. This method is commonly used with ethanol as an extractor solvent and requires a long period to complete the process. Alternative methods, such as ultrasound-assisted extraction, have been applied to optimize these processes. In this context, to evaluate the effect of extraction time, the ultrasound-assisted and the maceration extraction methods were performed on white bracts and flowers from Bougainvillea spectabilis Willd. (Nyctaginaceae). The antioxidant activities and fatty acid content of the different extracts were determined. The amount of phenolic compounds obtained for the maceration technique was greater, however, in the evaluation of the potential antioxidant activity by the DPPH and ABTS+ free radicals scavenging, no significant difference was verified when compared to the extraction by ultrasound for 30 minutes. In the determination of fatty acids by gas chromatography coupled with mass spectrometer it was found that the highest contents were of palmitic, linoleic, and stearic acids for both extraction methods. The 30 minutes of extraction by ultrasound proved to be the time necessary to quickly and efficiently extract the bioactive compounds from B. spectabilis. Thus, the use of ultrasound-assisted extraction, when compared to the maceration method, is an alternative for obtaining plant extracts in a short time, reducing the instability that some compounds.