USE OF A THERMOMECHANICAL ANALYZER - STUDY OF AN APPARENT GLASS-TRANSITION IN COOKIE DOUGH

The ThermoMechanical Analyzer (TMA) is a sensitive instrument that mea sures dimensional changes such as those occurring during glass transit ions. Knowledge of the glass transition temperature (T-g) may provide a better understanding of many food systems. Cookie dough is a food sy stem that appears to be affected greatly by an apparent glass transiti on of the flour protein. Hard-wheat-flour cookie doughs underwent an a pparent glass transition at a lower temperature (71 degrees C) than di d 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. S et time and apparent T-g were highly correlated (r=0.971 soft; r=0.989 hard).