title: The bread dough stability improving effect of pyranose oxidase from trametes multicolor and glucose oxidase from Aspergillus niger: unraveling the molecular mechanism.
abstract: Glucose oxidase (GO) and pyranose oxidase (P2O) improve dough stability and bread quality. We here studied whether their mode of action resides in cross-linking of proteins and/or arabinoxylan (AX) molecules through the production of H2O2. Evidence for both was deduced from a decrease in extractability of protein and AX from dough made with P2O, GO, or H2O2, using sodium dodecyl sulfate containing buffer and water, respectively. The addition of H2O2, P2O, or GO to a glutathione solution sharply decreased its sulfhydryl (SH) content. P2O or GO can trigger protein cross-linking through the formation of disulfide (SS) bonds. As a result thereof, SH/SS interchange reactions between low molecular mass SH containing compounds and gluten proteins can be hampered. Furthermore, a decrease in the level of monomeric ferulic acid (FA) esterified to AX in dough points to a role of FA bridges in cross-linking of AX molecules. Our results indicate that the molecular mechanism of dough and bread improvement by P2O and GO resides in cross-linking of gluten proteins and AX by formation of H2O2. They furthermore show that the extent of cross-linking upon addition of P2O or GO strongly depends on the concentration (and production rate) of H2O2.
authors.affiliation: Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20 - box 2463, B-3001 Heverlee, Belgium.
authors.forename: Karolien
authors.initials: K
authors.lastname: Decamps
authors.forename: Iris J
authors.initials: IJ
authors.lastname: Joye
authors.forename: Lalatiana
authors.initials: L
authors.lastname: Rakotozafy
authors.forename: Jacques
authors.initials: J
authors.lastname: Nicolas
authors.forename: Christophe M
authors.initials: CM
authors.lastname: Courtin
authors.forename: Jan A
authors.initials: JA
authors.lastname: Delcour
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology*; D001939:Bread / Q000032:analysis*; D002237:Carbohydrate Dehydrogenases / Q000737:chemistry*; D005656:Fungal Proteins / Q000737:chemistry*; D005949:Glucose Oxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis; D055454:Trametes / Q000201:enzymology*; D014908:Triticum / Q000737:chemistry*; D014990:Xylans / Q000737:chemistry
chemical_list: D005656:Fungal Proteins; D014990:Xylans; C085118:arabinoxylan; D006861:Hydrogen Peroxide; D002237:Carbohydrate Dehydrogenases; C022489:pyranose oxidase; D005949:Glucose Oxidase