Abstract:
Thai jasmine rice is an aromatic rice with variable prices due to the odorant from volatile gas called 2-acetyl-1-pyrroline (2AP), which a key odor-active compound contributing to the pleasant smell of the cooked rice. However, the 2AP was rapidly gone after 6 months of storage or at high temperature condition. Beta-cyclodextrin (βCD) and its derivatives (e.g. methyl (M) and hydroxypropyl (HP) βCDs) have been extensively used to enhance the stability of many volatile compounds through an encapsulation process into the lipophilic inner cavity. In the present study, the dynamics behavior and stability of inclusion complexes of 2AP with βCDs were studied using all-atom molecular dynamics simulations and Gibbs free energy calculations. The obtained results showed that the van der Waals driven encapsulation of 2AP could adapt the structures of the βCDs to become more stable conformers. The structural data and free energy results demonstrated that the 2,6-DMβCD is the most suitable host for 2AP encapsulation. In addition, the modified βCDs, especially 6-HPβCD and 2,6-DMβCD, could enhance the stability of 2AP better than natural βCD.
