Mathematical and computational modeling of fats and triacylglycerides.

Fats and oils are found in many food products; however, their macroscopic properties are difficult to predict, especially when blending different fats or oils together. With difficulties in sourcing specific fats or oils, whether due to availability or pricing, food companies may be required to find alternative sources for these ingredients, with possible differences in ingredient performance. Mathematical and computational modeling of these ingredients can provide a quick way to predict their properties, avoiding costly trials or manufacturing problems, while, most importantly, keeping the consumers happy.

Predicting Lipid Eutectics Using Coarse-Grained Molecular Dynamics.

Binary triacylglyceride (TAG) systems are known to exhibit nonlinear/eutectic behavior, and predicting this is not straightforward unless the thermodynamic properties of the constituent TAGs are known. While this kind of behavior has been shown previously using molecular dynamics, this was carried out using an atomistic force field and fully saturated symmetric TAGs. In this study, we simulate the changing melting point of binary unsaturated asymmetric TAG systems using a coarse-grained force field.

Triacylglyceride melting point determination using coarse-grained molecular dynamics.

This study is carried out using the COGITO force field to determine whether the thermodynamic melting point of pure triacylglyceride crystals can be predicted using molecular dynamics simulations. The triacylglycerides used in this study are both saturated and unsaturated, as well as symmetrical and asymmetrical, to test the robustness of both the force field and the direct heating methodology described in this paper. Given the nonequilibrium nature of a melting system, a larger number of simulations are required to ensure that the results are sufficiently converged, that is, with little fluctuation and a small confidence interval.

COGITO: A Coarse-Grained Force Field for the Simulation of Macroscopic Properties of Triacylglycerides.

The use of molecular dynamics 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 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.

Rapid Automated Quantification of Triacylglyceride Crystallinity in Molecular Dynamics Simulations.

The relative stability of crystalline polymorphs and the transition between crystalline and melt phases are key parameters in determining the physical properties of triacylglycerides used in food. However, while the determination of properties experimentally is well-defined, the ability to predict the onset of melting and discriminate between polymorphs is less well-defined within a molecular dynamics simulation environment. In this work, we present metrics for measuring the crystallinity, including a new metric, the near-neighbor occupancy time, giving a rapid determination of how many, and which, molecules are found in a crystal over a simulation trajectory, and the polymorphic determination of triacylglycerides over a simulation trajectory.

Reproduction of macroscopic properties of unsaturated triacylglycerides using a modified NERD force field.

Unsaturated triacylglycerides are found in many commonly consumed foods, such as cooking oils, nuts and chocolate. There are however very few publications on Molecular Dynamics simulations of such molecules, and, to the best of our knowledge, no such published research on crystalline mono-unsaturated triacylglycerides. The work described in this paper is an evaluation of different force fields (GROMOS96 and NERD) to determine the best force field parameters to reproduce the crystalline and melted macroscopic properties of such molecules accurately.