Improvement in Nutritional Attributes of Rice Starch with Dodecyl Gallate Complexation: A Molecular Dynamic Simulation and in Vitro Study

To improve starch functionalities such as digestibility and antioxidant activity, rice starch was complexed with antioxidant dodecyl gallate (DG). Molecular dynamics simulation showed that the starch-DG inclusion complex was favorable, and in 50 ns, the dodecyl segment resided in the helix of the amylose cavities but the gallate tail left outside. This theoretical finding was validated by UV-vis spectroscopy, calorimetric, and crystalline measurements, indicating V-type crystalline structures containing type I and type II inclusion complexes can be formed after DG complexation. Meritedly, starch digestibility was mitigated by synchronously increasing slowly digestible starch (5.12-22.83%) and resistant starch content (8.69-14.17%), and the antioxidant activity was also significantly increased. Such inclusion complexes thereby acted as a carrier for targeting delivery of DG to the human lower gastrointestinal tract with potent antioxidant activity. Complexation with DG synergistically improved starch digestibility and antioxidant activity, favoring the intervention against chronic diseases, by ameliorating the postprandial glycemic response and oxidative stress.