Extraction of nobiletin and tangeretin with antioxidant activity from peels of Citrus poonensis using liquid carbon dioxide and ethanol entrainer

Extraction of nobiletin and tangeretin from peels of Citrus poonensis was conducted with liquid CO2 and ethanol entrainer. Yields of nobiletin (6.7 mg/g-dry peel) and tangeretin (4.4 mg/g-dry peel) for liquid CO2 with ethanol entrainer extractions (25ºC, 10 MPa, 60 min with CO2-ethanol mole fraction of 0.13) gave 24% and 19% higher yields compared to conventional ethanol extraction. The DPPH radical scavenging activity of the extracts obtained from liquid CO2 with ethanol entrainer showed to be similar to ascorbic acid and α-tocopherol.