Dynamic mechanical thermal properties of frozen dough sheet

In order to search the change rule of frozen dough food, the glass transition temperature and it’s influence factors, dynamic-mechanical thermal properties of frozen dough sheet made from different wheat flour during temperature dropping from 20℃ to －80℃ and rising from －80℃ to 20℃ were investigated by using Dynamic Mechanical Thermal Analysis(DMTA). The results show that dynamic-mechanical thermal properties of frozen dough sheet made from wheat flour with different varieties, milling granules and water addition are different, especially in the glass transition temperature Tg′. During temperature rising from 20℃ to －80℃, Tg′ of coarse and fine wheat flour samples are －33.23℃ and －39.9℃ respectively; there are two Tg′ peak in high water sample, they are 41.42℃ and －42.97℃ respectively, Tg′ of low water sample is －33.23℃; During temperature rising from －80℃ to 20℃,Tg′ of sample X5 is 2.40℃, and sample X15 have three Tg′ peak, they are －7.97, －6.41 and 10.31℃; Tg′ of the coarse wheat flour sample C15 is 3.62℃, and there are three Tg′ in fine wheat flour sample, they are －7.97, －6.41 and 10.31℃; Tg′ of high and low water sample are －10.14℃ and 3.62℃ respectively. To keep wheat flour frozen dough food quality, it’s processing temperature should be the glass transition temperature, but not －18℃ used at present.