In the present work, the strong effects of the SC-CO2 fluid
extraction parameters on the extraction of lycopene from tomato
skin and on the antioxidant activity of the resulting extracts have
been demonstrated. Response surface methodology determined
that temperature, followed by pressure, was the most significantly
effective variable for the SC-CO2 fluid extraction. Lycopene yield
continued increasing within the range of temperature (40–100 C) and pressure (20–40 MPa) tested. The increase in flow rate
did not result in a significant increase in lycopene yield. Only when
the temperature of the supercritical extraction was increased
above 70 C did it show great influence on the antioxidant activity
and composition of the lycopene isomers. Similar to thermal processing,
the lycopene stability and antioxidant level of each unit
of lycopene-rich extract decreased with increasing the SC-CO2 fluid
extraction temperature above 70 C. No significant influences of
pressure and flow rate on the stability and antioxidant activities
of SC-CO2 fluid extraction products were observed.