title: Peroxidase-mediated oxidative cross-linking and its potential to modify mechanical properties in water-soluble polysaccharide extracts and cereal grain residues.
abstract: Analysis of wheat bran and spent grain shows that concentrations of ferulate and diferulates offer considerable scope to modify the cross-linking of feruloylated polysaccharides and hence the mechanical properties of these residues. In solution ferulic acid (FA) can be readily polymerized by horseradish peroxidase, but when esterified to a polysaccharide, the profile of diferulates becomes restricted. This situation also exists in muro and suggests structural constraints may limit the availability of FA for cross-linking. At relatively low polysaccharide concentration, (approximately 3%), steric restrictions were apparent in gels prepared using isolated polysaccharides. Mechanical properties such as swelling also appear to be fixed at these relatively low polysaccharide concentrations. This limits the potential to modify mechanical properties in muro through oxidoreductase activity. To modify mechanical properties such treatments will need to focus on increasing the "flexibility" of the cell wall matrix and the accessibility of enzymes to the cell wall matrix.
authors.affiliation: Sustainability of the Food Chain Exploitation Platform, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, United Kingdom. jim.robertson@bbsrc.ac.uk
authors.forename: James A
authors.initials: JA
authors.lastname: Robertson
authors.forename: Craig B
authors.initials: CB
authors.lastname: Faulds
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Smith
authors.forename: Keith W
authors.initials: KW
authors.lastname: Waldron
mesh_terms: D002473:Cell Wall / Q000201:enzymology* / Q000502:physiology; D003373:Coumaric Acids / Q000737:chemistry / Q000378:metabolism*; D004043:Dietary Fiber / Q000032:analysis / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide; D010084:Oxidation-Reduction; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D012995:Solubility; D014908:Triticum / Q000737:chemistry / Q000378:metabolism
chemical_list: D003373:Coumaric Acids; D004043:Dietary Fiber; D011134:Polysaccharides; C004999:ferulic acid; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase