Increasing cis-lycopene content of the oleoresin from tomato processing byproducts using supercritical carbon dioxide

“Natural” lycopene is expensive and can be obtained from tomatoes; therefore, commercial lycopene is mostly obtained from chemical synthesis. Tomato processing byproducts represent a low-cost source of high-value lycopene. Cis-lycopene is more bioavailable than trans-lycopene; however, 95% of the lycopene in tomato is in all-trans form. The objective of this study was to obtain a cis-lycopene-rich oleoresin from tomato peels and seeds using supercritical carbon dioxide (SC-CO2) and to compare it with the conventional hexane extraction. The highest oleoresin yield (246 g/kg) was obtained from 100% seeds; with SC-CO2 extraction at lower temperature (40 °C) and higher pressure (50 MPa), whereas the highest cis-lycopene content was obtained at higher temperature (80 °C) and lower pressure (30 MPa) from 100% peels. SC-CO2-extracted oleoresins contained up to 67% of cis-lycopene, whereas it was only 34% in the hexane-extracted ones. When the oleoresin was centrifuged, the upper oil fraction (supernatant) contained up to 82% of cis-lycopene. SC-CO2 can enhance the efficacy of lycopene during extraction stage in a simple and clean way.