Determination of lutein and zeaxanthin and antioxidant capacity of supercritical carbon dioxide extract from daylily (Hemerocallis disticha)

► Two major compounds, lutein and zeaxanthin, were identified in daylily flowers employing a very simple HPLC methodology. ► The optimal lutein and zeaxanthin extraction of SFE-CO2 could be achieved at 80 °C and 600 bar. ► The extraction pressure was the most important parameter for SFE-CO2. ► Daylily flowers extracts had higher antioxidant activities in all antioxidant assays.