THERMAL AND DYNAMIC-MECHANICAL PROPERTIES OF FROZEN WHEAT DOUGHS WITH ADDED SUCROSE,NaCl, ASCORBIC ACID,AND THEIR MIXTURES

The effects of sucrose, NaCl, and ascorbic acid on the physical state of wheat dough at sub-zero temperatures were investigated using Differential Scanning Calorimetry (DSC) and Dynamic-Mechanical Analysis (DMA). The DSC thermograms were obtained for annealed samples by scanning from ?80 to 10°C at 5°C/min. Added sucrose and NaCl decreased the onset of ice melting of doughs, and they were found at ?26°C. Added sucrose and NaCl increased the relative amount of unfrozen water in doughs, while added ascorbic acid had not noticeable effects. DMA measurements were made for annealed samples at a heating rate of 1°C/min from ?150 to 10°C. The loss modulus, G″, of DMA showed an α-relaxation (glass transition), two low temperature relaxations (β and γ), and melting of ice in all doughs with added ingredients.