Optimisation of biological and physical parameters for lycopene supercritical CO2 extraction from ordinary and high-pigment tomato cultivars

BACKGROUND: Lycopene is used for several industrial applications. Supercritical CO2 (SC-CO2) extraction from red-ripe tomato fruits is an excellent technique to replace the use of harmful solvents. In this study, starting from red-ripe tomatoes of ordinary and high-lycopene cultivars, the effect of different agronomical and technical aspects on lycopene content, stability and yield was evaluated throughout the production process from fresh tomatoes to the final SC-CO2-extracted oleoresin containing lycopene. RESULTS: Red-ripe tomato cultivars differed in their lycopene content. Irrigation excess or deficit caused an increase in the amount of lycopene in the fruits. Fresh tomatoeswere processed into a lyophilised matrix suitable for SC-CO2 extraction,which could be stored for more than 6months at -20 oC without lycopene loss. Under the optimal extraction conditions, efficiencies of up to 80% were achieved, but the recovery of lycopene in the extracted oleoresin was very low (~24%). Co-extraction of the tomato matrix mixedwith a lipid co-matrix allowed the recovery of~90% of lycopene in the oleoresin. Using the high-lycopene cultivars, the yield of total extracted lycopene increased by ~60% with respect to the ordinary cultivars. Lipids and other biologically active molecules were present in the oleoresin. CONCLUSION: A method for extracting, from a tomato matrix, a natural and solvent-free oleoresin containing lycopene dissolved in a highly unsaturated vegetable oil has been described. The oleoresin represents an excellent product for testing on cancer and cardiovascular disease prevention.