Supercritical fluid extraction of lycopene from tomato juice and characterization of its antioxidation activity

A new method to extract lycopene from tomato juice using supercritical CO2 as solvent and without the need to dry the raw material is presented. To conduct the extraction, the tomato juice was subjected to cycles of centrifugation followed by rinsing with absolute ethanol to partially remove the water present in the solid part of the juice. The influence of the temperature and pressure on the extraction efficiency and on the extract antioxidant activity was studied using a factorial experimental design. The extraction efficiency varied from 7.7% to 76.7% and only extraction temperature had a statically significant effect on the process. The reversed phase HPLC analysis showed that lycopene is the major compound of the extract. The extract that presented higher antioxidant activity was obtained at 40 °C and 350 bar with 12.7 mmol L−1 Trolox/g of extract using the DPPH radical scavenging method and 61.3 mmol L−1 Trolox/g of extract using the rubrene singlet oxygen quenching method.