Use of a thermomechanical analyzer - Study of an apparent glass transition in cookie dough

The ThermoMechanical Analyzer (TMA) is a sensitive instrument that measures dimensional changes such as those occurring during glass transitions. Knowledge of the glass transition temperature (T-g) may provide a better understanding of many food systems. Cookie dough is a food system that appears to be affected greatly by an apparent glass transition of the flour protein. Hard-wheat-flour cookie doughs underwent an apparent glass transition at a lower temperature (71 degrees C) than did soil-wheat-flour cookie doughs (78 degrees C). Decreasing the sugar level in the dough decreased both the set time and the apparent T-g. Set time and apparent T-g were highly correlated (r=0.971 soft; r=0.989 hard).