EFFECTS OF MOISTURE, SUCROSE, NaCl, AND ARABINOXYLAN ON RELAXATION IN WHEAT DOUGH AS MEASURED BY DMTA

Abstract

The effects of sucrose, NaCl, and arabinoxylan on the α-relaxation of wheat doughs with different water contents were investigated using Dynamic Mechanical Thermal Analysis (DMTA). DMTA measurements were made at the heating rate of 2°C/min from at least 30°C below the observed onset of the α-relaxation (glass transition) to at least 30°C above the transition. The glass transition temperature, Tg , was taken from the onset temperature of the decrease in storage modulus (G′). The frequencies used were 0.1, 1, and 5 Hz and amplitude was 16 μm. The storage modulus, G′, showed α-relaxation in all doughs with added ingredients. Added ingredients decreased the glass transition temperature of dough. The Tg of doughs with different ingredients decreased with increasing water content of doughs over the whole aw range used (0.113–0.753). Also, the Tg increased with increasing frequency.