Effect of moisture migration on texture and viscoelasticity of Chinese yam during multi-phase microwave drying (MMD) - focusing on the evaporation-dehydration stage

This study aimed to assess the correlation between moisture migration and texture, as well as viscoelasticity of Chinese yam during the evaporation stage of multiphase microwave drying (MMD). A comparison of different drying strategies (Scheme I, Scheme II, and Scheme III) revealed that the water molecule mobility decreased as drying proceeded. In samples with higher water content at the transition point, the rapid migration of water during evaporation stage could result in a more pronounced collapse of the cellular and pore structure, leading to a denser product with increased hardness. Additionally, changes in the samples' textural and viscoelastic properties were significantly correlated with the moisture states. As water mobility decreased, the movement of molecular chains was restricted, leading to increased rigidity in the sample. These findings can provide theoretical guidance for the process optimization of MMD to meet consumers' demand for high-quality dried products.