Application of Green Technology for the Acquisition of Extracts of Araçá (Psidium grandifolium Mart. ex DC.) Using Supercritical CO2 and Pressurized Ethanol: Characterization and Analysis of Activity.

ABSTRACT

Brazil is home to a wide variety of flora, including several lesser known species, such as araçá that were processed in this study using two green technologies consecutively supercritical fluid extraction (SFE) for nonpolar fraction and pressurized liquid extraction. For polar fraction, the experiments followed a central composite design involving ethanol as solvent, with temperature and static time in each bath as independent variables. Both extracts were analyzed for antioxidant and antimicrobial activities. Total phenolics content (TPC) was determined for all ethanol extracts. In the araçá essential oil (AEO) obtained by SFE, the extraction yield was 2.33%. The three major compounds of AEO were α-pinene (20.75%), p-cymene (20.50%), and o-cymene (20.05%). In ethanol extracts, the high yield (14.49%) was obtained at 74 °C/6 min and the major TPC (136.95 mg GAE/100 g) at 60 °C/9 min. Ethanol extracts presented good antioxidant activity (EC50 = 6.37 mg/mL) at 74 °C/6 min. AEO was unable to reduce DPPH• concentration by 50%. Both extract types presented an inhibitory effect against Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus cereus, while only the ethanol extracts presented effect against Listeria monocytogenes. This work had the aim to present the innovation of the use of a whole typical Brazilian fruit that gives rise to extracts with excellent properties for employment in both the pharmaceutical and food industries.