Starch gelatinization kinetics in bread dough - DSC investigations on 'simulated' baking processes

Starch gelatinization in wheat flour dough of various moisture contents was quantitatively evaluated by means of DSC. The experimental records were wo rked out in the form of excess heat capacity vs. T traces which were deconv oluted to single out the contribution of starch gelatinization from that of the decomposition of amylose-lipid complexes. The quantitative procedure u sed put into evidence that a third endothermic process would take place in the dough with a poor moisture content. DSC runs carried out with sealed pans (i.e., at constant moisture level) an d open pans (from which some water was free to evaporate) allow simulation of two extreme conditions of a real baking process, namely that relevant to the central core and to superficial layer of a dough loaf, respectively. T he extent of starch gelatinization occurred in these conditions was quantit atively assessed. These data were collected at various heating rates and us ed to define temperature-time-transformation (TTT) diagrams which are usefu l tools to predict the progress of baking for any given thermal history of the system.