Cereals & Grains Association
Log In

A new glucose oxidase from Penicillium for baking application
C. VAN BENSCHOP (1). (1) DSM Food Specialties, Delft, Netherlands

Glucose oxidase (GOX) has been used widely in baking for many years – working as an oxidant to improve measures such as strain-hardening index and elasticity in dough,  and  to improve dough performance during processing - as well as the shape and volume of the baked bread. GOX oxidizes glucose to gluconic acid, using atmospheric oxygen and, importantly, to produce hydrogen peroxide. Its mode of action in dough is not well characterized but hydrogen peroxide produced from the enzyme has been variously speculated to lead to the oxidation of gluten protein, non-gluten protein, glutathione and/or hemicellulose fractions. 

We describe a GOX from Penicillium (PenGOX) and consider it in relation to the enzyme from Aspergillus niger (AspGOX). Our results in baking show that  PenGOX is more effective than AspGOX. Depending on flour type we see a significant increase in dough stability, elasticity and fineness of the crumb while maintaining good dough handling properties. We speculate how this can be explained from the differences in kinetics of  the enzymes and the affinities they show towards oxygen and glucose.  The availability of oxygen and glucose will be in a state of flux during the early stages of making dough and these substrates can be presumed to make impact on the activity of the two enzymes. Our data show that the Km of PenGOX for glucose is 3-fold lower compared to that of AspGOX. Surprisingly no differences in affinity towards oxygen were observed. We have also examined the influence of these enzymes on thiol and disulfide groups within the dough, in terms of overall protein and glutathione. Dough samples were taken at several time points during kneading and proofing and stabilized in acid environment to inactivate the enzyme. This allows us to speculate on the underlying mechanism of GOX in dough and brings further insight on how the two products differ.

View Presentation