Tocopherols, Tocomonoenols, and Tocotrienols in Oils of Costa Rican Palm Fruits: A Comparison between Six Varieties and Chemical versus Mechanical Extraction

Palm oil is one of the richest sources of tocotrienols and may contain other non-tocopherol vitamin E congeners. The vitamin E profiles of fully ripened fruit mesocarp of three Elaeis guineensis, two Elaeis oleifera, and one hybrid O x G palm fruit genotypes from Costa Rica were analyzed by high-performance liquid chromatography with fluorescence detection and gas chromatography-mass spectrometry after mechanical extraction by a screw press and chemical extraction with hexane. gamma-Tocotrienol, alpha-tocotrienol, and alpha-tocopherol were the most abundant tocochromanols, while other tocopherols (beta-tocopherol, gamma-tocopherol, and delta-tocopherol) and alpha-tocomonoenol were detected at minor concentrations. Significant differences in vitamin E profiles between genotypes were observed, and the variety E. oleifera Quepos (CB9204) had by far the highest content of total tocotrienols (890 mu g/g of oil) and total vitamin E (892 mu g/g of oil). Chemical extraction with hexane afforded up to 2.5-fold higher vitamin E yields than screw press extraction. alpha-Tocomonoenol co-eluted with gamma-tocopherol in reversed-phase highperformance liquid chromatography analyses and is a possible source of error in the quantification of gamma-tocopherol in foods.