EXTRACTION OF CAROTENOIDS FROM TOMATO BY NEAR CRITICAL LIQUID CO2

Carotenoids such as lycopene and β-carotene are gaining interest in the food industry due to their nutritional and antioxidant properties. In this study we investigated the use of near critical liquid CO2, as a solvent for the extraction of lycopene and β-carotene from tomato pulp and tomato skin. Two different procedures were tested: the extraction of tomato pulp and tomato skin via continuous solvent recycling and the extraction by a Soxhlet-type process via periodic solvent recycling. The extraction was carried out in a Jennings-type autoclave. The kinetics of the extraction, and the lycopene and β-carotene content of the liquid CO2 extracts were determined for both extraction procedures. The results for the content of lycopene and β-carotene in liquid CO2 tomato extracts were compared to those obtained by Soxhlet extraction of tomato pulp using as solvents n-hexane and dichloromethane. HPLC-DAD was used for the quantification of the lycopene and β-carotene in the extracts as described by Vasopollo. Extraction by Soxhlet-type periodic recycling of liquid CO2 is more efficient (9.2-17.31 ?g lycopene/g tomato skin and 9.33-20.67 ?g β-carotene /g tomato pulp) than continuous recycling of liquid CO2 (0.087-2.53 ?g lycopene/g tomato and 0.94-8.89 ?g β-carotene /g tomato). The highest β-carotene content was found in tomato pulp extracted with liquid carbon CO2 and in the n-hexane extracts of tomato skin (1370 ?g lycopene/g tomato and 78 ?g β-carotene /g tomato).