Extraction of Lycopene from Tomato Skin and Pulp with Supercritical CO{sub}2

摘要

Considering the Mother Nature, a solution to recovering natural extracts such as carotenoids free of chemical additives by using supercritical carbon dioxide technology was tried to be found in this research. Supercritical carbon dioxide (SCCO{sub}2) extraction of lycopene from waste tomato skins was investigated as a first work. The experiments were carried out in 10 mL extraction vessel at pressures and temperatures ranging from 20 to 50 MPa and 313 to 373 K, respectively, without using any modifiers at 2.5 mL/min CO{sub}2 flow rate for 330 min extraction time. Solvent flow rate effect was examined for CO{sub}2 flow rates from 1.5 to 4.5 mL/min. The extracts were analyzed by high-performance liquid chromatography and UV-visible spectroscopy. Chromatographic analysis indicated that lycopene was extracted from tomato skin with negligible degradation at the optimum operating conditions; 40 MPa, 373 K, and 2.5 mL of CO{sub}2/min and the amount extracted represented more than 94% of the total carotenoid content of the sample. Extractions of lycopene, β-carotene and lutein using supercritical CO{sub}2 from tomato pulps, which are almost all of the waste after tomato processing, were further important study subsequent to previous work. The extraction efficiency of lycopene with 56% recovered from dried tomato pulps using SCCO{sub}2 at the optimum operating conditions in 10 mL extraction vessel increased by using EtOH as co-solvent up to 91.7%. Water and acetone were other co-solvents used during the extractions of carotenoids. In the scope of commercial production, large scale SCCO{sub}2 extraction of lycopene from tomato pulp with and without using co-solvent was performed in 100 mL and 1L extractors. Similar yields and chromatographic fingerprints were obtained for extracts prepared using analytical and large scale (1L) equipment under comparable conditions. Other than this, it was shown that the yield of extraction was mostly affected by applied CO{sub}2 flow rate due to the change in extraction size.