Glucose 2-oxidase (pyranose oxidase, pyranose:oxygen-2-oxidoreductase, EC 1.1.3.10) catalyses the oxidation of d-glucose and some other carbohydrates in their pyranose forms at carbon 2 in the presence of molecular oxygen producing the corresponding carbonyl sugar and hydrogen peroxide (Machida and Nakanishi, 1984). The oxidation of d-glucose results in the formation of d-glucosone (2-keto-d-glucose; d-arabino-2-hexosulose) and hydrogen peroxide (Oliveira et al., 1992).