Flowers and Leaves of Tropaeolum majus L. as Rich Sources of Lutein

ABSTRACT: As increasing evidence supports the role of lutein and zeaxanthin in reducing the risk of cataract and macular degeneration, food sources of these carotenoids are being sought. In the present study, the lutein content of the edible flowers and leaves of Tropaeolum majus L. was determined by high-performance liquid chromatography-photodiode array detector (HPLC-PDAD), complemented by HPLC-mass spectrometry (MS) for identification. Chemical reactions were also used as identifying parameters. The yellow and brownish orange flowers had 450 ± 60 μg/g and 350 ± 50 μg/g lutein, respectively. Violaxanthin, antheraxanthin, zeaxanthin, zeinoxanthin, β-cryptoxanthin, α-carotene, and β-carotene were also detected at very low levels. The leaves had 136 ± 18 μg/g lutein, 69 ± 7 μg/g β-carotene, 74 ± 23 μg/g violaxanthin, and 48 ± 13 μg/g neoxanthin. Lutein was partly esterified in the flowers and unesterified in the leaves. The flowers of T. majus are therefore excellent food sources of lutein and the leaves good sources of both lutein and the provitamin A β-carotene.