title: Carotene and novel apocarotenoid concentrations in orange-fleshed Cucumis melo melons: determinations of β-carotene bioaccessibility and bioavailability.
abstract: Muskmelons, both cantaloupe (Cucumis melo Reticulatus Group) and orange-fleshed honeydew (C. melo Inodorus Group), a cross between orange-fleshed cantaloupe and green-fleshed honeydew, are excellent sources of β-carotene. Although β-carotene from melon is an important dietary antioxidant and precursor of vitamin A, its bioaccessibility/bioavailability is unknown. We compared β-carotene concentrations from previously frozen orange-fleshed honeydew and cantaloupe melons grown under the same glasshouse conditions, and from freshly harvested field-grown, orange-fleshed honeydew melon to determine β-carotene bioaccessibility/bioavailability, concentrations of novel β-apocarotenals, and chromoplast structure of orange-fleshed honeydew melon. β-Carotene and β-apocarotenal concentrations were determined by HPLC and/or HPLC-MS, β-carotene bioaccessibility/bioavailability was determined by in vitro digestion and Caco-2 cell uptake, and chromoplast structure was determined by electron microscopy. The average β-carotene concentrations (μg/g dry weight) for the orange-fleshed honeydew and cantaloupe were 242.8 and 176.3 respectively. The average dry weights per gram of wet weight of orange-fleshed honeydew and cantaloupe were 0.094 g and 0.071 g, respectively. The bioaccessibility of field-grown orange-fleshed honeydew melons was determined to be 3.2 ± 0.3%, bioavailability in Caco-2 cells was about 11%, and chromoplast structure from orange-fleshed honeydew melons was globular (as opposed to crystalline) in nature. We detected β-apo-8'-, β-apo-10', β-apo-12'-, and β-apo-14'-carotenals and β-apo-13-carotenone in orange-fleshed melons (at a level of 1-2% of total β-carotene). Orange-fleshed honeydew melon fruit had higher amounts of β-carotene than cantaloupe. The bioaccessibility/bioavailability of β-carotene from orange-fleshed melons was comparable to that from carrot (Daucus carota).
authors.affiliation: Department of Human Nutrition, The Ohio State University, Columbus, Ohio 43210, United States.
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Fleshman
authors.forename: Gene E
authors.initials: GE
authors.lastname: Lester
authors.forename: Ken M
authors.initials: KM
authors.lastname: Riedl
authors.forename: Rachel E
authors.initials: RE
authors.lastname: Kopec
authors.forename: Sureshbabu
authors.initials: S
authors.lastname: Narayanasamy
authors.forename: Robert W
authors.initials: RW
authors.lastname: Curley
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Schwartz
authors.forename: Earl H
authors.initials: EH
authors.lastname: Harrison
mesh_terms: D001682:Biological Availability; D018938:Caco-2 Cells; D002338:Carotenoids / Q000032:analysis / Q000493:pharmacokinetics*; D028463:Cucumis melo / Q000737:chemistry*; D004063:Digestion; D005638:Fruit / Q000737:chemistry; D006801:Humans; D008954:Models, Biological; D019207:beta Carotene / Q000032:analysis / Q000493:pharmacokinetics*
chemical_list: D019207:beta Carotene; D002338:Carotenoids; C004984:apocarotenal