title: Polyacetylenes in fresh and stored carrots (Daucus carota): relations to root morphology and sugar content.
abstract: BACKGROUND
  Carrot roots contain polyacetylenes, reported to be both beneficial and distasteful when consumed by humans. This study aimed to investigate the relationships between polyacetylene contents, root morphology and sugar content in order to increase the opportunities to optimise the composition of polyacetylenes in carrots.
  
  
  RESULTS
  The falcarinol/total polyacetylene ratio was positively correlated with root size, the amount of sucrose and the sucrose/total soluble sugar ratio among both fresh and stored samples. Root size was inversely correlated with the amounts of falcarindiol and falcarindiol-3-acetate, especially among stored samples. Stored carrots exhibited an inverse correlation between polyacetylenes and the amount of soluble sugar. At a falcarinol content at harvest below approximately 200 mg kg(-1) dry weight the amounts of all polyacetylenes increased during storage, but above that level the amounts of all polyacetylenes instead decreased.
  
  
  CONCLUSIONS
  The results indicate similarities in the activity of the enzymes transforming sucrose to hexoses and the enzymes transforming falcarinol to falcarindiol-3-acetate and falcarindiol. The negative correlation between root size and polyacetylenes seems to be partly due to dilution but also to a higher synthetisation rate in smaller roots. The results indicate the existence of an equilibrium regulating the level of falcarinol.
authors.affiliation: Department of Horticulture, Swedish University of Agricultural Sciences, PO Box 103, SE-230 53 Alnarp, Sweden. lars.kjellenberg@slu.se
authors.forename: Lars
authors.initials: L
authors.lastname: Kjellenberg
authors.forename: Eva
authors.initials: E
authors.lastname: Johansson
authors.forename: Karl-Erik
authors.initials: KE
authors.lastname: Gustavsson
authors.forename: Marie E
authors.initials: ME
authors.lastname: Olsson
mesh_terms: D018552:Daucus carota / Q000201:enzymology / Q000378:metabolism*; D004032:Diet; D019422:Dietary Sucrose / Q000378:metabolism*; D053280:Diynes / Q000378:metabolism*; D004798:Enzymes / Q000378:metabolism*; D005233:Fatty Alcohols / Q000378:metabolism*; D061353:Food Storage; D006601:Hexoses / Q000378:metabolism; D006801:Humans; D018517:Plant Roots / Q000033:anatomy & histology*; D012995:Solubility; D013395:Sucrose / Q000378:metabolism*
chemical_list: D019422:Dietary Sucrose; D053280:Diynes; D004798:Enzymes; D005233:Fatty Alcohols; D006601:Hexoses; C018541:falcarinol; C034379:falcarindiol; D013395:Sucrose