Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/24/2010
Publication Date: 7/1/2010
Citation: Eller, F.J., Moser, J.K., Kenar, J.A., Taylor, S.L. 2010. Extraction and Analysis of Tomato Seed Oil. Journal of the American Oil Chemists' Society. 87:755-762. Interpretive Summary: This research demonstrated that the antioxidant capacity of tomato seed oil is a function of two lycopene isomers. Tomato seed oil is a potentially valuable product from waste seeds which represents a very large by-product of processed tomato. Hot ethanol was found to be the most effective extraction method to extract oil from ground tomato seeds. Several phytosterols were found in the extracted oils, including sitosterol, cycloartanol, and stigmasterol and the most abundant antioxidants found in the tomato seed oils were all trans lycopene, cis 3 lycopene and beta-carotene. Oxygen radical absorbance capacity (ORAC) values were positively correlated with only cis 2 lycopene and all trans lycopene, demonstrating their role as antioxidants in the tomato seed oil. These results will assist those interested in finding new uses for tomato seeds, especially the use of antioxidant rich tomato seed oil.
Technical Abstract: Tomato seeds represent a very large waste by-product from the processing of tomatoes into products such as tomato juice, sauce and paste. One potential use for these seeds is as a source of vegetable oil. This research investigated the oil content of tomato seeds using several extraction techniques as well as an examination of the oil extracts to determine the composition of the minor constituents, such as phytosterol and antioxidant composition. The oxygen radical absorbance capacity (ORAC) of the tomato seed oils were also measured and correlated with antioxidant contents. This research demonstrated that tomato seed oil yield was highest using hot ethanol, followed by hot hexane and finally supercritical carbon dioxide (SC-CO2). The SC-CO2 treatment, however, had the highest total phytosterol content as well as each individual phytosterol content. Sitosterol, cycloartanol and stigmasterol were the most abundant phytosterols present in the extracts. The highest concentrations of antioxidants were found in the hexane extract. The most abundant antioxidants found in the tomato seed oils were all trans lycopene, cis 3 lycopene and beta-carotene. ORAC capacity was highest for the Hexane extract. Oil yield was inversely proportional to both a-tocopherol and '-tocopherol content and positively correlated with lycopene cis 3 content. ORAC values were positively correlated with only lycopene all trans and lycopene cis 3 demonstrating their role as antioxidants in the tomato seed oil.