Effects of glucose oxidase, hemicellulase and ascorbic acid on dough and bread quality

Abstract

In this study, glucose oxidase alone or its combinations with hemicellulase or ascorbic acid were used in bread making. Glucose oxidase alone mainly decreased dough extensibility. It produced stiffer and less extensible dough. Combinations of glucose oxidase-hemicellulase presented lower extensibility and were more resistant to extension than glucose oxidase alone. When glucose oxidase-ascorbic acid combinations were used, the softening degree significantly decreased, regardless when added the lowest glucose oxidase in combination with ascorbic acid. Glucose oxidase-ascorbic acid combinations significantly modified dough resistance. The glucose oxidase alone significantly increased specific loaf volume. The Dallman value of loaves made with glucose oxidase alone was found higher than for control. The most dramatic effect of additives on specific loaf volume was observed when glucose oxidase-hemicellulase combinations were added. This effect has been ascribed to redistribution of water from the hemicellulose to gluten, which would render the gluten more extensible. Specific loaf volume showed a significant enhancement when glucose oxidase-ascorbic acid combinations were added, but this effect was not as good as glucose oxidase-hemicellulase. The effects of glucose oxidase and its combinations with ascorbic acid and hemicellulase on dough rheology and bread quality are highly dependent on the amount of enzyme and the original wheat flour quality.