Biochemical characteristics of Trametes multicolor pyranose oxidase and Aspergillus niger glucose oxidase and implications for their functionality in wheat flour dough

Similar to glucose oxidase (GO), pyranose oxidase (P2O) may well have desired functionalities in some food applications in general, particularly breadmaking. As its name implies, P2O oxidises a variety of monosaccharides. P2O purified from a culture of Trametes multicolor (P2O-Tm) had high affinity towards d-glucose (KM = 3.1 mM) and lower affinity to other monosaccharides. GO from Aspergillus niger (GO-An) had a KM value of 225 mM towards glucose, which points to a significant difference in glucose affinity between the two enzymes. Furthermore, P2O-Tm had higher affinity towards O2 (KM = 0.46 mM) than GO-An (KM = 2.9 mM). Dehydroascorbic acid did not accept electrons in the reactions catalysed by P2O-Tm and GO-An. For the same activity towards glucose in saturating conditions, the rate of ferulic acid oxidation in a model system and of thiol oxidation in a wheat flour extract were higher with P2O-Tm, than with GO-An. The demonstrated differences in properties and functional features between P2O-Tm and GO-An allow prediction of differences in functional behaviour of the enzymes, in food applications.