title: Impact of pre-harvest light spectral properties on health- and sensory-related compounds in broccoli florets.
abstract: BACKGROUND
  Plants grown at different latitudes experience differences in light spectral composition. Broccoli (Brassica oleracea L. var italica) plants were grown in climate-controlled chambers under supplemental wavelengths (red, far-red, red + far-red or blue) from light-emitting diodes (LEDs). The light treatments were combined with two cold climate temperatures (12 and 15 °C) during broccoli head formation to investigate the effects on morphology and content of health- and sensory-related compounds: glucosinolates, flavonols, ascorbic acid and soluble sugars.
  
  
  RESULTS
  Supplemental far-red and red + far-red light led to elongated plants and the lowest total glucosinolate content in broccoli florets. The content of quercetin was highest with supplemental red light. Vitamin C was not significantly affected by the light treatments, but 12 °C gave a higher content than 15 °C.
  
  
  CONCLUSIONS
  The effects of supplemental red and far-red light suggest an involvement of phytochromes in the regulation of glucosinolates and flavonols. A shift in red:far-red ratio could cause changes in their content besides altering the morphology. The sugar and vitamin C content appears to be unaffected by these light conditions. Supplemental blue light had little effect on plant morphology and content of the health- and sensory related compounds.
authors.affiliation: Bioforsk - Norwegian Institute for Agricultural and Environmental Research, NO-9269, Tromsø, Norway.
authors.forename: Anne Linn Hykkerud
authors.initials: AL
authors.lastname: Steindal
authors.affiliation: Bioforsk - Norwegian Institute for Agricultural and Environmental Research, NO-9269, Tromsø, Norway.
authors.forename: Tor J
authors.initials: TJ
authors.lastname: Johansen
authors.affiliation: Bioforsk - Norwegian Institute for Agricultural and Environmental Research, NO-9269, Tromsø, Norway.
authors.forename: Gunnar B
authors.initials: GB
authors.lastname: Bengtsson
authors.affiliation: Nofima - Norwegian Institute of Food, Fisheries and Aquaculture Research, NO-1431, Ås, Norway.
authors.forename: Sidsel F
authors.initials: SF
authors.lastname: Hagen
authors.affiliation: Bioforsk - Norwegian Institute for Agricultural and Environmental Research, NO-9269, Tromsø, Norway.
authors.forename: Jørgen A B
authors.initials: JA
authors.lastname: Mølmann
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry / Q000378:metabolism; D001937:Brassica / Q000737:chemistry / Q000528:radiation effects*; D044948:Flavonols / Q000737:chemistry / Q000378:metabolism; D005961:Glucosinolates / Q000737:chemistry / Q000378:metabolism; D008027:Light; D009753:Nutritive Value / Q000528:radiation effects
chemical_list: D044948:Flavonols; D005961:Glucosinolates; D001205:Ascorbic Acid
keywords: ascorbic acid; glucosinolates; kaempferol; light quality; quercetin; temperature