American Chemical Society, Books and Journals Division
Journal of Agricultural and Food Chemistry vol:61 issue:32 pages:7848-7854
Glucose oxidase (GO) and pyranose oxidase (P2O) improve dough stability and bread quality. We here studied whether their mode of action resides in crosslinking 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. Addition of H2O2, P2O or GO to a glutathione solution sharply decreased its sulfhydryl (SH) content. P2O or GO can trigger protein crosslinking through 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 crosslinking of AX molecules. Our results indicate that the molecular mechanism of dough and bread improvement by P2O and GO resides in crosslinking of gluten proteins and AX by formation of H2O2. They furthermore show that the extent of crosslinking upon addition of P2O or GO strongly depends on the concentration (and production rate) of H2O2.