Orange-fleshed Cucumis melo Melons: Determinations of Beta-carotene Bioaccessibility and Bioavailability

β-carotene from melon (Cucumis melo) is an important dietary antioxidant and precursor of vitamin A, but its bioaccessibility/bioavailability is unknown. We compared β-carotene concentrations from previously frozen orange-fleshed honey dew and cantaloupe melons grown under the same glasshouse conditions, and from freshly harvested field-grown, orange-fleshed honey dew melon to determine β-carotene bioaccessibility/bioavailability. β-carotene 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 (ug/g dry weight) for the orange-fleshed honey dew and cantaloupe were 242.8 and 176.3, respectively. The average dry weights per gram of wet weight of orange-fleshed honey dew and cantaloupe were 0.094 g and 0.071 g, respectively. The bioaccessibility of field-grown, orange-fleshed honey dew melons was determined to be 3.2±0.3 %, bioavailability in Caco-2 cells was about 11%, and chromoplast structure from orange-fleshed honey dew melons was globular (as opposed to crystalline) in nature. The bioaccessibility/bioavailability of β-carotene from orange-fleshed melons was comparable to that from carrot (Dacus carota).