Supercritical carbon dioxide extraction of lycopene in tomato skins

The lycopene in dried and powdered tomato skins was extracted with supercritical carbon dioxide at flowrate of 1.5 ml/min, at different temperatures and with various modifiers. Extracts were analyzed by high-performance liquid chromatography. Relative recovery of 100% of total lycopene was achieved (at 110 °C and 400 atm) in 50 min, both without modifier and with acetone, but acetone speeded up the beginning of the extraction, leading to a relative recovery of 94% in just 15 min. The maximum recovery was higher than with conventional solid-liquid extraction (SLE). The decrease in the amount of lycopene as a function of storage time was followed, and the effect of storage conditions on recovery was tested. The stability of lycopene stored in solvent was improved through the addition of (+)-α-tocopherol or rosemary extract.