title: Photoinduced isomerization of lycopene and application to tomato cultivation.
abstract: The present study aimed to investigate if growth conditions have an impact on the isomeric composition of lycopene in tomatoes. First a model system for photoinduced isomerization was established. Tomato extracts were irradiated with a halogen lamp, whose wavelength spectrum is close to the spectrum of daylight and thus mimics field-grown cultivation. Different optical filters were interposed between lamp and samples to simulate greenhouse conditions. 5-cis-Lycopene was formed preferentially while the concentration of 7-cis-lycopene decreased in field-grown model systems. The change of isomerization in greenhouse model systems led to a significantly different ratio. Consequently 5-cis- and 7-cis-lycopene were identified as potent markers for the differentiation of various lighting conditions during cultivation. This result was verified in biological samples. Authentic field-grown tomatoes (var. Lycopersicon esculentum Mill. var. commune L. H. Bailey "Harzfeuer") showed a significantly higher content of 5-cis-lycopene 5.90 ± 0.45% compared to tomatoes of the same variety grown under electric lighting 4.11 ± 0.10%. Additionally, the ratio of 7-cis-lycopene was significantly lower under field-grown conditions.
authors.affiliation: Institute of Chemistry, Food Chemistry, Martin-Luther-University Halle-Wittenberg , Kurt-Mothes-Strasse 2, 06120 Halle/Saale, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Heymann
authors.forename: Julia
authors.initials: J
authors.lastname: Raeke
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Glomb
mesh_terms: D002338:Carotenoids / Q000737:chemistry* / Q000378:metabolism; D005638:Fruit / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D007536:Isomerism; D008027:Light; D000077276:Lycopene; D018551:Solanum lycopersicum / Q000737:chemistry* / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D002338:Carotenoids; D000077276:Lycopene