Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 16, 2006
Publication Date: April 16, 2006
Citation: Perkins Veazie, P.M., Collins, J.K., Davis, A.R., Roberts, B.W. 2006. Carotenoid content of 50 watermelon cultivars. Journal of Agricultural and Food Chemistry. 54:2593-2597.
Interpretive Summary: Most watermelons enjoyed by consumers have sweet red flesh. The red in watermelon is from lycopene, a pigment found to be medically important in prevention of some cancers and types of heart disease. Seeded and seedless watermelon varieties were tested for their lycopene content to determine the range in pigment concentration. Most watermelon varieties were found to be high in lycopene and the seedless varieties tested often had more lycopene than seeded types. The results of this study indicate that most watermelon varieties used for commercial sales to grocery stores are a rich source of lycopene.
Red-fleshed watermelon contains lycopene, a carotenoid with antioxidant properties. Identification of germplasm with high amounts of lycopene may help plant breeders and medical researchers develop new uses for natural sources of lycopene. This study was conducted to evaluate lycopene content in commercial cultivars of seeded and seedless red-fleshed watermelons over a five-year period. Spectrophotometric and scanning colorimetric assays of total lycopene were used to separate 65 watermelon cultivars into average (<50 mg/kg fw), high (50-70), very high (70-90), and exceptional (>90) lycopene content categories. Seedless types were usually in the high and very high ranges. Seeded cultivars that were open-pollinated and light red in color (Black Diamond, Calhoun Gray, Crimson Sweet) had an average lycopene concentration, most hybrids had a high concentration, and a few were in the very high range. Carotenoid profiles of watermelons indicated that trans- lycopene was the predominant carotenoid (84-97%) and cultivars differed in the relative amounts of cis-lycopene, beta-carotene, and phytofluene. All carotenoids were correlated to each other. Quadratic relationships were seen between phytofluene and total lycopene and betciween phytofluene and total carotenoids. Phytofluene and beta-carotene had a strong linear relationship. These results demonstrate that red-fleshed watermelon genotypes have the same carotenoid pattern, but relative amounts of carotenoids, especially lycopene, can vary extensively.