title: Ascorbate pool, sugars and organic acids in black currant (Ribes nigrum L.) berries are strongly influenced by genotype and post-flowering temperature.
abstract: BACKGROUND
  Marked effects of the climatic environment on fruit chemical composition have often been demonstrated in field experiments. However, complex covariations of several climatic factors in the natural environment complicate the interpretation of such experiments and the identification of the causal factors. This can be better achieved in a phytotron where the various climatic factors can be varied systematically. Therefore, we grew four black currant cultivars of contrasting origin in a phytotron under controlled post-flowering temperature and photoperiod conditions and analysed the berries for their ascorbic acid, sugar and organic acid contents.
  
  
  RESULTS
  The analyses revealed significant effects of genotype on all investigated compounds. Particularly large cultivar differences were observed in the concentrations of l-ascorbic acid (AA) and sucrose. The concentrations of both AA and dehydroascorbic acid (DHAA), as well as the concentrations of all major sugars, decreased consistently with an increasing temperature over the temperature range 12-24 °C. Fructose and glucose were the predominant sugars with concentrations several fold higher than that for sucrose. AA was the main contributor to the total ascorbate pool in black currant berries. The AA/DHAA ratio varied from 5.6 to 10.3 among the studied cultivars. The concentration of citric acid, which was the predominant organic acid in black currant berries, increased with an increasing temperature, whereas the opposite trend was observed for malic and shikimic acid. Quninic acid was always present at relatively low concentrations. By contrast, photoperiod had no significant effect on berry content of any of the investigated compounds.
  
  
  CONCLUSIONS
  It is concluded that the post-flowering temperature has marked effects on the concentration of important chemical compounds responsible for taste and nutritional value of black currant berries, whereas photoperiod has no such effect in the studied cultivars. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Plant Sciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway.
authors.forename: Tomasz L
authors.initials: TL
authors.lastname: Woznicki
authors.affiliation: NIBIO, Norwegian Institute for Bioeconomy Research, NO-1431, Ås, Norway.
authors.forename: Anita
authors.initials: A
authors.lastname: Sønsteby
authors.affiliation: Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Osloveien 1, NO-1430, Ås, Norway.
authors.forename: Kjersti
authors.initials: K
authors.lastname: Aaby
authors.affiliation: Nofima, Norwegian Institute of Food, Fisheries and Aquaculture Research, Osloveien 1, NO-1430, Ås, Norway.
authors.forename: Berit K
authors.initials: BK
authors.lastname: Martinsen
authors.affiliation: Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, NO-1432, Ås, Norway.
authors.forename: Ola M
authors.initials: OM
authors.lastname: Heide
authors.affiliation: Department of Plant Sciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway.
authors.forename: Anne-Berit
authors.initials: AB
authors.lastname: Wold
authors.affiliation: Department of Plant Sciences, Norwegian University of Life Sciences, NO-1432, Ås, Norway.
authors.forename: Siv F
authors.initials: SF
authors.lastname: Remberg
mesh_terms: D000143:Acids / Q000378:metabolism*; D000383:Agriculture; D001205:Ascorbic Acid / Q000378:metabolism*; D003683:Dehydroascorbic Acid / Q000378:metabolism; D035264:Flowers; D005632:Fructose / Q000378:metabolism; D005638:Fruit / Q000737:chemistry*; D005838:Genotype; D005947:Glucose / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism*; D006801:Humans; D009753:Nutritive Value; D017440:Photoperiod; D031965:Ribes / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013045:Species Specificity; D013395:Sucrose / Q000378:metabolism*; D013696:Temperature
chemical_list: D000143:Acids; D006601:Hexoses; D005632:Fructose; D013395:Sucrose; D005947:Glucose; D001205:Ascorbic Acid; D003683:Dehydroascorbic Acid
keywords: dehydroascorbic acid; l-ascorbic acid; organic acids; photoperiod; sugars; temperature