title: Biochemical basis of color as an aesthetic quality in Citrus sinensis.
abstract: The biochemical basis of color as an aesthetic quality in mature fruit of navel and Valencia orange (Citrus sinensis) was determined. Saponification of the two major color-imparting components resolved by thin-layer chromatography, followed by reversed-phase high-performance liquid chromatography, revealed that these comprised acyl esters of (9Z)-violaxanthin and beta-citraurin. Identification of the chromophores was based on cochromatography and online spectral analysis. The color quality of flavedo of mature fruit was dependent on the content and relative amounts of (9Z)-violaxanthin and beta-citraurin. Quantitative results revealed that increased color intensity was associated with a decline in the (9Z)-violaxanthin:beta-citraurin ratio from greater than 50 to below 10, an increase in flavedo (9Z)-violaxanthin and beta-citraurin content, and that measurement of the mass and ratio of these carotenoids can be used to accurately color-grade orange fruit for local and export markets.
authors.affiliation: Department of Medical Chemistry, Faculty of Medicine, Pécs University, Szigeti út 12, P.O. Box 99, H-7601, Hungary.
authors.forename: R
authors.initials: R
authors.lastname: Oberholster
authors.forename: A K
authors.initials: AK
authors.lastname: Cowan
authors.forename: P
authors.initials: P
authors.lastname: Molnár
authors.forename: G
authors.initials: G
authors.lastname: Tóth
mesh_terms: D002338:Carotenoids / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D002957:Citrus / Q000737:chemistry*; D003116:Color; D010860:Pigments, Biological / Q000032:analysis*; D024341:Xanthophylls; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D010860:Pigments, Biological; D024341:Xanthophylls; C428343:citraurin; D019207:beta Carotene; D002338:Carotenoids; C005613:violaxanthin