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 CO(2) (SC-CO(2)) 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-CO(2)-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 tomatoes were processed into a lyophilised matrix suitable for SC-CO(2) extraction, which could be stored for more than 6 months at -20 degrees C 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 (approximately 24%). Co-extraction of the tomato matrix mixed with a lipid co-matrix allowed the recovery of approximately 90% of lycopene in the oleoresin. Using the high-lycopene cultivars, the yield of total extracted lycopene increased by approximately 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.

First-time comparison of the in vitro antimalarial activity of Artemisia annua herbal tea and artemisinin.

Artemisia annua tea has been proven to be a very effective treatment for malaria in various clinical trials, but to date its efficacy has not been investigated in vitro. A study was therefore performed to evaluate the effects of A. annua tea on Plasmodium falciparum cultures in vitro. The concentration of artemisinin in the herbal tea preparation was also determined. The herbal tea extract was tested against chloroquine (CQ)-sensitive D10 and CQ-resistant W2 strains of P. falciparum using the parasite lactate dehydrogenase assay. Quantification of artemisinin in the extract of leaves of A. annua was performed using proton nuclear magnetic resonance ((1)H-NMR). Results of the in vitro tests were consistent with the clinical efficacy of A. annua tea [50% inhibitory concentration (IC(50)) for strain D10=1.11±0.21 µg/ml; IC(50) for strain W2=0.88±0.35 µg/ml]. The concentration of artemisinin in A. annua tea (0.18±0.02% of dry weight) was far too low to be responsible for the antimalarial activity. The artemisinin present in the tea is probably co-solubilised with other ingredients, some of which also have antimalarial activity and act synergistically with it. These compounds also merit further research to determine whether their presence hinders the development of parasite resistance compared with pure artemisinin.