Effect of Glass Transition on the Relaxation Properties and Drying Crack of Various Components of the Maize Kernels

During the drying process of maize kernels ( Zea mays L.), variations in moisture and temperature can induce a glass transition, resulting in changes to relaxation properties that ultimately lead to drying‐induced cracking. However, the mechanisms by which the glass transition affects relaxation properties and subsequently causes crack formation remain unclear. This study aims to investigate the stress relaxation and glass transition behaviors of various components of maize kernels, as well as to explore the relationship between changes in relaxation properties and drying‐induced cracking. Our findings indicate that both glass transition and relaxation properties are influenced by moisture content and temperature. The components of maize kernels exhibit distinct glass transition behaviors, leading to varying changes in their relaxation properties. During the drying process, the pericarp and germ maintain a single state, thereby avoiding crack formation. In contrast, cracks predominantly develop in the endosperm due to significant alterations in relaxation properties associated with the glass transition. As the maize kernels cool, the temperature decreases from the drying temperature to the cooling temperature, facilitating a transition to a glassy state, which primarily contributes to crack formation during this cooling stage. This study provides insights into the mechanisms of crack formation and may assist in optimizing operational conditions for maize drying.