Supercritical carbon dioxide extraction of carotenoids, tocopherols and sitosterols from industrial tomato by-products

In this work the supercritical carbon dioxide extraction of biologically active, high valued compounds such as carotenoids (lycopene, β-carotene), tocopherols, fatty acids and sitosterols from industrial tomato waste was investigated. The differences of two samples of different sources and the effect of air-dried and deep-frozen storages were also reported. The effects of extraction parameters (pressure and temperature) on the extraction yields and the compositions of the products were determined with statistical analysis. Supercritical fluid extraction was compared to conventional extraction processes of tomato pomace samples. The extracts were analysed by gas chromatography, by high-performance liquid chromatography and by TLC-densitometry. The extraction yields and the amounts of lycopene, tocopherols and sitosterols depend on the experimental conditions. The product obtained by supercritical CO2 extraction at 460 bar and 80 °C contained the highest concentration of carotenoids with 90.1% of lycopene, while products rich in tocopherols and phytosterol were obtained above 300 bar and 40 °C.