Compressed fluids extraction methods, yields, antioxidant activities, total phenolics and flavonoids content for Brazilian Mantiqueira hops

This study compares the yields of different extractions methods for a Brazilian variety of Humulus lupulus using scCO2, scCO2 + ethanol, scCO2 + ethyl acetate, and compressed propane. Extracts were characterized by total phenolics content (TPC), total flavonoid content (TFC), and antioxidant activity (AA). The extraction yields were from 2.7 to 10.1 wt% when using compressed propane at 20 °C and 10 MPa and scCO2 + ethyl acetate at 80 °C and 25 MPa, respectively. Furthermore, the effect of adding ethyl acetate as a cosolvent in a semi-batch process over the extraction time and extracts properties were evaluated in comparison to the extracts obtained using scCO2, scCO2 + ethanol, and compressed propane. The results indicate that ethyl acetate increases the extraction yield and produces samples with higher TPC, TFC, and AA values comparing to scCO2 + ethanol and similar values compared to pure scCO2.