Research on the Influence of Moisture State, Microscopic Morphology and Physical Properties of the Resting Dough

Abstract

To study the effect of resting on the quality of frozen dough, the changes in the moisture state of the dough during the resting process (0, 30, 60, 90, 120 min), the moisture distribution of dough and their effects on ice crystal distribution, microstructure, and creep recovery characteristics after dough freezing were investigated. The results showed that the freezable water content in the dough was decreased by 0.96% with the extension of the resting time. The pores and number of ice crystals formed in the dough during the freezing process gradually decreased and the distribution of ice crystals became more and more uniform. The average pore area decreased from 22.65 to 11.80 with the extension of the resting time from 0 min to 120 min, and the number of pores decreased from 22.65 to 11.80 with the extension of the resting time. The maximum creep flexibility Jmax increased significantly (P<0.05) and the zero shear viscosity η0 decreased significantly (P<0.05) during the creep phase as the resting time was extended. After resting for 120 mins, the maximum creep flexibility Jmax of frozen dough decreased by 0.50×10−4 Pa−1, and the zero shear viscosity η0 decreased by 0.43×105 Pa−1. This indicated that the hardness of frozen dough decreases and the shape of the dough was easier to maintain. During the recovery process, the instantaneous flexibility J0 and viscoelastic flexibility Jm increased by 1.26×10−4 and 2.88×10−4 Pa−1, respectively, and the recovery force of the frozen dough increased. In summary, resting process of dough would reduce the content of freezeable water, improve the water holding capacity, and reduce the damage of ice crystals to the dough network structure in the freezing process to improve the quality of the frozen dough.

Keywords

• resting
• moisture state
• microstructure
• freeze dough