Structural changes in fasted state dietary mixed micelles upon solubilization of beta-carotene

Authors : Beste BAYRAMOĞLU

Pages : 480-493

Doi:10.31015/jaefs.2022.3.18

View : 18 | Download : 9

Publication Date : 2022-09-23

Article Type : Research Paper

Abstract :It was aimed to investigate the structural changes taking place in duodenal mixed micelles insert ignore into journalissuearticles values(MM); at fasted state with the incorporation of fatty acids insert ignore into journalissuearticles values(FA); and the morphological transformations in these MMs upon solubilization of β-carotene insert ignore into journalissuearticles values(BCR); through coarse-grained insert ignore into journalissuearticles values(CG); molecular dynamics insert ignore into journalissuearticles values(MD); simulations. All simulations were performed with GROMACS 2019 simulation package using the Martini force field. Lauric acid insert ignore into journalissuearticles values(LA);, stearic acid insert ignore into journalissuearticles values(SA); and linoleic acid insert ignore into journalissuearticles values(LNA); were used to explore the effects of FA chain length and unsaturation. Micelle swelling was observed with the incorporation of all FAs. The increase in size was in line with increasing FA chain length and unsaturation. MMs incorporating LA and SA were ellipsoidal in shape, while polyunsaturated LNA resulted in a worm-like MM. Upon solubilization of BCRs, swelling was observed only in the MMs with long-chain SA and LNA. No micelle growth was observed in the plain and LA MMs despite their smaller sizes. This was attributed to their low-density hydrophobic cores, which allowed a condensation effect induced by the interactions between BCRs and POPC tails. It is inferred that when the micelle is large enough to solubilize BCRs, whether or not swelling will take place depends on the core density. The increase in micelle size was very small in the MM incorporating LNA compared to that in the MM with SA, which was accompanied by an elliptical-to-cylindrical shape transformation. This was due to the fluid nature of the worm-like LNA micelle, which readily allowed the solubilization of 3 BCRs within its core. By resolving the internal structures of BCR incorporated MMs, this study gives valuable insight into the effects of FA chain length and unsaturation on the solubilization behavior of dietary MMs. The results are expected to give direction to the development of rational design strategies for effective BCR delivery systems.
Keywords : Molecular dynamics simulation, β carotene, dietary mixed micelle, bioaccessibility, nutraceutical delivery system