A NEW APPROACH TO STUDY STARCH CHANGES OCCURRING IN THE DOUGH-BAKING PROCESS AND DURING BREAD STORAGE

Wheat starch gelatinization taking place during the baking of differen t bread dough recipes was studied by differential scanning calorimetry (DSC), simulating the baking conditions in the centre of bread crumb samples. After heating, dough samples were kept in DSC pans to evaluat e amylopectin retrogradation at different storage times. Results were compared with those obtained from a calorimetric study of lyophilized bread crumb samples. Both methods showed that similar retrogradation r ates occurred. In this work, dough heating methodology was applied in order to study the influence of water content and dough freezing on st arch gelatinization and retrogradation. Maximum retrogradation was obs erved to occur when the water content was between 35 and 50%. Dough fr eezing had no significant effect on starch gelatinization, but it incr eased the retrogradation rate when the storage of frozen dough was pro longed to 30 days. Heating wheat flour dough in the calorimeter afford ed direct information about the behaviour of starch in the dough syste m and about its retrogradation during storage. This method appears to be as a simple and reliable way to evaluate the influence of component s and processing conditions on the physico-chemical changes of starch.