Structuring of 2-oleodipalmitin at the air interface from all-atom, united-atom, and coarse-grained molecular dynamics simulations

This study employs classical molecular dynamics (MD) simulations to investigate the behavior of 1,3-dipalmitoyl-2-oleoyl glycerol (POP), a typical triglyceride found in food at the air interface. The investigation utilizes three force fields (FF) with varying levels of detail, including all-atom, united-atom, and coarse-grained simulations, to elucidate the structural evolution of POP at the air interface. The results confirm that the structuring processes observed in nonfood triglyceride systems also occur in POP. Aliphatic chains orient toward the air phase, while glycerol backbones face the inner triglyceride phase. Additionally, the study observes the formation of clusters of glycerol head groups at the interface, and the choice of the FF significantly affects the simulated morphological structure. The Berger FF exhibits the most substantial structuring effects after 200 ns of simulation, followed by the General AMBER FF, while the Martini FF shows the weakest effects. Number density plots of aliphatic chains and glycerol backbones at different temperatures monitor the evolution of structuring effects over time and determine the approach toward equilibrium conditions. The temperatures investigated include the solid state of POP at ambient temperature (293 K), the liquid state at human body temperature (310 K), and a typical processing temperature of the chocolate conching process (333 K). Practical Applications: Tailored molecular design of interfaces according to their purpose in food.