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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. The study also highlights the importance of the presence of defects, in this case as voids, to lower the melting nucleation energy barrier of the crystals and avoid superheating of the systems being tested. The size of these defects is much larger than what would be found in a physical crystal, however, the simple and robust procedure that was developed allows the accurate prediction of melting points of the different triacylglycerides.

We characterise the yield behaviour and flow curve of a commercially available, molten, tempered milk chocolate with a fat content of 30%, from rheological measurements performed with a rotational rheometer fitted with a four-bladed vane spindle in a large-gap setup. We show that the yield behaviour can be captured by the viscoelastic White-Metzner model, which indicates that elastic deformation precedes flow as the shear stress is increased. Following an initial fluidisation cycle, the shear modulus of the tempered chocolate increases by a factor sixty to G = 4.4 × 10 4 Pa. We find that the Bingham model provides the best fit to our extensive flow curve data, where the yield stress is τ yield = 36.1 ± 0.6 Pa and the Newtonian plateau viscosity is µ B = 8.7 ± 0.02 Pa s.

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