The water properties of frozen dough were measured by NMR over the temperature range from -70℃ to 5℃.The thawing process of dough was also studied by MRI.The water in dough can be divided into two portions

that are the half-bound water

the T2 of which is ≈ 10ms

and the deep-bound water

the T2 of which is ≈ 2ms. During freezing

the half-bound water partly form to ice and the other change to unfreezale water. The deep-bound water did not change or move. So improving the ratio of deep-bound water in dough is benefit to frozen dough production and inhibiting ice crystals generating. According different NMR data

it is confirmed that the glass transition of dough occurs at -30℃ and the ice melting at -9℃. The water in frozen dough can be classified into three parts and they are the solid ice (29.71%)

the real unfreezable water (22.2%)

the deep-bound water (33.81%).