Maximizing the Concentrations of Wheat Grain Fructans in Bread by Exploring Strategies To Prevent Their Yeast (Saccharomyces cerevisiae)-Mediated Degradation

The degradation of endogenous wheat grain fructans, oligosaccharides with possible health-promoting potential, during wheat whole meal bread making was investigated, and several strategies to prevent their degradation were evaluated. Up to 78.4 +/- 5.2% of the fructans initially present in wheat whole meal were degraded during bread making by the action of yeast (Saccharomyces cerevisiae) invertase. The addition of sucrose to dough delayed fructan degradation but had no effect on final fructan concentrations. However, yeast growth conditions and yeast genotype did have a clear impact. A 3-fold reduction of fructan degradation could be achieved when the commercial bread yeast strain was replaced by yeast strains with lower sucrose degradation activity. Finally, fructan degradation during bread making could be prevented completely by the use of a yeast strain lacking invertase. These results show that the nutritional profile of bread can be enhanced through appropriate yeast technology.