title: Soluble and cell wall-bound phenolic acids and ferulic acid dehydrodimers in rye flour and five bread model systems: insight into mechanisms of improved availability.
abstract: BACKGROUND
  The bread-making process influences bread components, including phenolics that significantly contribute to its antioxidant properties. Five bread model systems made from different rye cultivars were investigated to compare their impact on concentration of ethanol-soluble (free and ester-bound) and insoluble phenolics.
  
  
  RESULTS
  Breads produced by a straight dough method without acid addition (A) and three-stage sourdough method with 12 h native starter preparation (C) exhibited the highest, genotype-dependent concentrations of free phenolic acids. Dough acidification by direct acid addition (method B) or by gradual production during prolonged starter fermentation (24 and 48 h, for methods D and E) considerably decreased their level. However, breads B were enriched in soluble ester-bound fraction. Both direct methods, despite substantial differences in dough pH, caused a similar increase in the amount of insoluble ester-bound fraction. The contents of phenolic fractions in rye bread were positively related to activity level of feruloyl esterase and negatively to those of arabinoxylan-hydrolysing enzymes in wholemeal flour.
  
  
  CONCLUSIONS
  The solubility of rye bread phenolics may be enhanced by application of a suitable bread-making procedure with respect to rye cultivar, as the mechanisms of this process are also governed by a response of an individual genotype with specific biochemical profile.
authors.affiliation: Department of Plant Biochemistry and Physiology, Plant Breeding and Acclimatization Institute - National Research Institute, Radzikow, PL-05-870, Blonie, Poland.
authors.forename: Wioletta M
authors.initials: WM
authors.lastname: Dynkowska
authors.forename: Malgorzata R
authors.initials: MR
authors.lastname: Cyran
authors.forename: Alicja
authors.initials: A
authors.lastname: Ceglińska
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000737:chemistry; D001939:Bread / Q000032:analysis* / Q000382:microbiology; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry* / Q000201:enzymology / Q000378:metabolism; D003296:Cooking; D003373:Coumaric Acids / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D056625:Endosperm / Q000737:chemistry / Q000201:enzymology; D000431:Ethanol / Q000737:chemistry; D005285:Fermentation; D005433:Flour / Q000032:analysis*; D006026:Glycoside Hydrolases / Q000378:metabolism; D062385:Hydroxybenzoates / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D011044:Poland; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism; D012434:Secale / Q000737:chemistry* / Q000201:enzymology; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013045:Species Specificity; D014783:Viscosity; D000067348:Whole Grains / Q000737:chemistry* / Q000201:enzymology; D014995:Xylosidases / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003373:Coumaric Acids; D062385:Hydroxybenzoates; D010940:Plant Proteins; D012997:Solvents; D000431:Ethanol; C004999:ferulic acid; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase; D006026:Glycoside Hydrolases; D014995:Xylosidases; C019713:alpha-N-arabinofuranosidase; C017616:phenolic acid
keywords: arabinoxylan-hydrolysing enzymes; ferulic acid dehydrodimers; feruloyl esterase; phenolic acids; rye (Secale cereale L.) bread