Bread quality and dough rheology of enzyme-supplemented wheat flour

The enzymatic treatment of wheat flours is an interesting alternative for improving their functional properties. Since enzymes with different biochemical activities could induce synergistic effects on dough behaviour or product quality, the individual and combined use of a wide range of enzymes (transglutaminase, glucose oxidase, laccase, α-amylase, pentosanase and protease) applied nowadays in bread-making processes were investigated. The blend of enzymes resulted in an improvement in the rheological behaviour of doughs and the quality of the final product. The simultaneous presence of transglutaminase (TG) and glucose oxidase (GO), as well as TG and protease (PROT) led to a synergistic effect on alveograph parameters. Polysaccharide-degrading enzymes exercised a significant effect on rheology only when used in combination with other enzymes, mainly affecting consistograph parameters. Analysis of bread-making data revealed significant interactions between TG and all the other enzymes except laccase (LAC). Significant synergistic effect on bread quality was observed by the combined use of GO and LAC, GO and pentosanase (PP), amylase (AMYL) and LAC, AMYL and PROT, and PP and PROT. Bread quality parameters showed greater correlations with alveograph parameters than with consistograph properties of dough. Tenacity (P) and extensibility (L) proved to be acceptable predictors of the height/width ratio of loaves. The duration of the alveograph test enhanced the prediction of bread quality parameters. Conversely, none of the rheological properties studied showed a high correlation with the specific volume of loaves.