Effect of laccase and manganese peroxidase on wheat gluten and pentosans during mixing

Wheat gluten and water extractable pentosans (WEP) were mixed in a batch-mi xer in the presence of laccase or manganese peroxidase (MnP). The enzymes p rovoked different changes in mixing behaviour. Doughs were analysed at time to peak (t) and over two t.(2t or overmixed). The effects of the oxidative enzymes were studied on femlic acid (FA), arabinoxylans (AX), proteins and possible intermolecular associations in these dough systems. Changes in ma cromolecular structures were followed using reverse phase-high performance liquid chromatography of phenolic compounds, AX extractability and the visc osity measurements, size exclusion-high performance Liquid chromatography a nd sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins. T he oxidative enzymes increased dough consistency, accelerated the loss in t otal FA, decreased AX water extractability and water extractable AX apparen t intrinsic viscosity in the dough water extracts. The effects of laccase a nd MnP were similar on femloylated AX when compared on a reaction time basi s. No covalent complex between AX and protein was detected in mixed and oxi dised gluten/WEP. (C) 2001 Elsevier Science Ltd. All rights reserved.