Occurrence of cis isomers of provitamins A in Brazilian vegetables

dc.creatorGodoy, HT
dc.creatorRodriguez-Amaya, DB
dc.date1998
dc.dateAUG
dc.date2014-12-02T16:29:27Z
dc.date2015-11-26T16:53:22Z
dc.date2014-12-02T16:29:27Z
dc.date2015-11-26T16:53:22Z
dc.date.accessioned2018-03-28T23:40:29Z
dc.date.available2018-03-28T23:40:29Z
dc.identifierJournal Of Agricultural And Food Chemistry. Amer Chemical Soc, v. 46, n. 8, n. 3081, n. 3086, 1998.
dc.identifier0021-8561
dc.identifierWOS:000075478100029
dc.identifier10.1021/jf9708655
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/67532
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/67532
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/67532
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1276562
dc.descriptionBecause cis isomerization lowers provitamin A activity, concern has been raised over the necessity of separating the provitamin A isomers in determining the vitamin A values of foods. Sixteen different raw vegetables and eight cooked vegetables (total of 123 samples) were analyzed to appraise the occurrence of cis isomers. The raw vegetables analyzed, except tomato and carrot, had cis isomers (trace to 3.4 mu g/g 13-cis-beta-carotene and trace to 4.1 mu g/g 9-cis-beta-carotene). The trans-beta-carotene range was 1.1-38.4 mu g/g. Appreciable amounts of alpha-carotene were found only in carrot (16.5-19.0 mu g/g trans-alpha d-carotene) and in a cultivar of squash (0.3 mu g/g 13-cis-alpha-carotene, 17.1 mu g/g trans-alpha-carotene, and 0.1 mu g/g g-cis-ol-carotene). The vitamin A values were calculated with and without isomer separation, using currently accepted biological activities, showing overestimations of 10-22% when the isomers were not separated. Cis isomers were found in all samples of cooked vegetables analyzed; the overestimations ranged from 5 to 20%. Isomer separation may be necessary for some vegetables, but the biopotency of the isomers has to be reevaluated.
dc.description46
dc.description8
dc.description3081
dc.description3086
dc.languageen
dc.publisherAmer Chemical Soc
dc.publisherWashington
dc.publisherEUA
dc.relationJournal Of Agricultural And Food Chemistry
dc.relationJ. Agric. Food Chem.
dc.rightsfechado
dc.sourceWeb of Science
dc.subjectprovitamin A determination
dc.subjectcarotenoid geometric isomers
dc.subjectvegetables
dc.subjectPerformance Liquid-chromatography
dc.subjectTrans Carotenoid Isomers
dc.subjectBeta-carotenes
dc.subjectHplc Separation
dc.subjectStructural Elucidation
dc.subjectProcessed Fruits
dc.subjectStationary-phase
dc.subjectAlpha-carotene
dc.subjectIdentification
dc.subjectFresh
dc.titleOccurrence of cis isomers of provitamins A in Brazilian vegetables
dc.typeArtículos de revistas


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