COGITO: a coarse-grained force field for the simulation of macroscopic properties of triacylglycerides

The use of molecular dynamics (MD) simulations is becoming ever more widespread, however, the application of this to pure triacylglyceride (TAG) systems, is not. In this study we are presenting the development, and validation, of a new force field (FF), which we have called the COarse-Grained Interchangeable Triacylglyceride-Optimized (COGITO) FF. The FF has been developed using both a bottom-up and top-down approach for different parameters, with the non-bonded parameters being optimized using a Bayesian Optimization method. While the FF was developed using mono-unsaturated TAGs, results show that it is also suitable for fully saturated TAGs. Description of molecules which were not used during the development of the FF is done simply by interchanging the bead in the molecule topologies. Results show that the FF can reproduce the macroscopic properties (density and lattice parameters) of pure TAGs as both crystals and melt with high accuracy, as well as reproduce the differences in enthalpies.