Exploring the moisture absorption behaviours of microwave-processed wheat starch-stearic acid complexes from a molecular view

The ambient humidity significantly affects the quality characteristics of starch-lipid complexes, and the moisture absorption behaviours remain further explored. In this study, microwave-processed wheat starch-stearic acid (WS-SA) complexes were prepared, of which the moisture absorption mechanism was investigated using experimental methods and molecular dynamics (MD) simulation. Results showed that the denser structure could endow the WS-SA complexes with lower equilibrium moisture (M_e = 19.0 %) as compared with the pure WS (M_e = 27.7 %), indicating their higher wetting resistance. MD simulation showed that the amylose-SA could effectively prevent water infiltration by the denser structures and the hydrophobicity of the non-complexed SA. This study reveals the moisture absorption behaviours of WS-SA complexes from a molecular view, embodying the theoretical and scientific significance of the current work. For future industrial reference, the current work can guide the development of humidity control strategies to mitigate the quality deterioration risks of starch-lipid complexes.