Evaluation of moisture migration and microstructure of quick-frozen wet rice flour after freeze-thaw cycles and changes in texture, cooking, and sensory properties.

Abstract

This study investigated the quality changes of quick-frozen wet rice flour before and after freeze-thaw cycles. As the freeze-thaw cycle was prolonged, the water mobility of quick-frozen wet rice flour decreased and the pore size and porosity of the microstructure increased. As a result, the hardness, cooking loss, water absorption, and water precipitation of the rice flour increased, while the sensory score and viscosity decreased. Correlation analysis showed that porosity was positively correlated with the hardness and water absorption of rice flour, and negatively correlated with structural properties such as shearing work and resilience. Water absorption and water precipitation rate were positively related to cooking loss. Thus, moisture migration in rice flour induced microstructural changes to cause alterations in texture, cooking, and sensory properties. Interestingly, quick-frozen wet rice flour still possessed good texture, cooking, and sensory qualities after two freeze-thaw cycles. This study laid the foundation for the development of high-quality quick-frozen wet rice flour.