EFFECT OF FOOD PREPARATION ON QUALITATIVE AND QUANTITATIVE DISTRIBUTION OF MAJOR CAROTENOID CONSTITUENTS OF TOMATOES AND SEVERAL GREEN VEGETABLES

The major carotenoid constituents of extracts from several raw and cooked green vegetables (broccoli, green beans, spinach), red ripe tomatoes, and tomato paste have been identified and quantified by high-performance liquid chromatography on a C18 reversed-phase column. The predominant carotenoids in raw green vegetables were neoxanthin, violaxanthin, lutein epoxide, lutein, alpha-carotene, and beta-carotene. The carotenoids in tomatoes and tomato paste were lutein, 5,6-dihydroxy-5,6-dihydrolycopene, lycopene 1,2-epoxide, lycopene 5,6-epoxide, lycopene, neurosporene, gamma-carotene, zeta-carotene, beta-carotene, phytofluene, and phytoene. The effect of various means of cooking on the levels of carotenoids in raw and cooked (microwaved, boiled, steamed, stewed) green vegetables and tomatoes has been extensively studied. It was shown that while the epoxycarotenoids were somewhat sensitive to heat treatment, lutein and hydrocarbon carotenoids such as neurosporene, alpha- and beta-carotene, lycopene, zeta-carotene, phytofluene, and phytoene survived the heat treatments.