Supercritical CO2 extraction of antioxidants from Paulownia elongata x fortunei leaves

Paulowniawood demand is increasing, but other parts of the tree remain underused. The leaves have medicinal properties, and their processing with a clean technology was explored. Supercritical fluid extraction (SFE) was proposed for the production of extracts fromPaulownia elongata x fortuneileaves. Three isotherms (35 degrees C, 45 degrees C, and 55 degrees C) were studied in the pressure range of 10-30 MPa to assess their influence on the extraction yield and antiradical properties. The use of ethanol as cosolvent was also evaluated. A global extraction yield of 4 g extract /100 g of leaves was obtained at 30 MPa and 45 degrees C using 10% ethanol (w/w) as modifier; the last fractions reached up to 0.30 g Trolox eq./g extract. Serial extractions with different concentrations of ethanol (60, 70, 80, and 96%) were performed. The global yield obtained with 70% ethanol in three stages was 32.9 g extract/100 g leaves, and the antiradical capacity of the first stage extract was equivalent to 0.4 g Trolox/g extract. Extraction kinetics was studied, and overall extraction curves were represented using Sovova's model.

Automated summary

The study explored the supercritical fluid extraction (SFE) of Paulownia elongata x fortunei leaves, finding that with the use of ethanol as a modifier, the extraction yield and antiradical properties can be enhanced under certain temperature and pressure conditions.