Effect of the addition of enzymes on the quality of frozen pre-baked French bread substituted with whole wheat flour

The objective of this study was to evaluate the effect of adding enzymes on the quality of frozen, pre-baked French bread, substituted with whole wheat flour. A central composite rotational design was used, varying the doses of the enzymes glucolipase, hemicellulase and hexose oxidase as the independent variables. The results were analyzed by Response Surface Methodology. The dependent variables were the process parameters (high-speed mixing and proofing times) and the quality characteristics of the rolls (specific volume, crumb texture, oven spring, shape, cut opening and cut height). The enzymes influenced the proofing time, crumb firmness of the pre-baked bread, the oven spring, shape, cut opening and cut height. Mathematical models for these variables as a function of the concentrations of the different enzymes were found and validated, and for some of the parameters, the enzymes showed interaction effects. For the high-speed mixing time and specific volume, models could not be established as a function of the three enzymes studied. The response surfaces obtained from the models for the cut opening and cut height were very similar, showing that the enzymes studied influenced these two parameters in the same way. (C) 2012 Elsevier Ltd. All rights reserved.