Speaker
Description
Introduction: Digestion of the milk lipids in our intestines yields monoglycerides and fatty acids that self-assemble into a variety of liquid crystalline structures. This self-assembly process is species dependent,[1,2] suggesting an important role for these structures in infant nutrition. Our recent work on the SAXS/WAXS beamline has focussed on studying how the lipid compositions of different milks generates different self-assembled structures both by digesting milk and analysing the by-products and assembling lipid mixtures that replicate the milk of different species from readily available fats and oils.
Methods: Small angle X-ray scattering (SAXS) with in situ lipolysis was used to measure the lipid self-assembly in various types of milk and infant formulae during digestion.[3] The structures observed were correlated with the resulting digestion products using a combination of liquid chromatography coupled to mass spectrometry (LCMS) and principle component analysis (PCA).[4] Lipid mixtures were prepared in the lab by mixing either homotriglycerides or natural fats and oils. These lipid mixtures were dispersed to form milk-like emulsions and their lipid self-assembly during digestion was compared with the milks and infant formulae.
Results & Discussion: This presentation will discuss the lipid liquid crystalline structures formed in a variety of milks and milk-like emulsions during digestion and how they can be mimicked. The lipid self-assembly in cow and human milk was shown to be replicated when the right balance of emulsified lipids was prepared by mixing homotriglycerides or blending milk fat with natural oils.[5] These emulsions provide representative digestive colloid structures through which to analyse the impact of lipid composition on self-assembly and bioactive delivery.
References
[1] Clulow, A. J.; Salim, M.; Hawley, A.; Boyd, B. J. A closer look at the behaviour of milk lipids during digestion. Chem. Phys. Lipids 2018, 211, 107-116.
[2] S. Salentinig, S. Phan, A. Hawley, B. J. Boyd, Angew. Chem. Int. Ed. 2015, 54, 1600-1603.
[3] Warren, D. B.; Anby, M. U.; Hawley, A.; Boyd, B. J. Real Time Evolution of Liquid Crystalline Nanostructure during the Digestion of Formulation Lipids Using Synchrotron Small-Angle X-ray Scattering. Langmuir 2011, 27 (15), 9528-9534.
[4] Pham, A. C.; Peng, K.-Y.; Salim, M.; Ramirez, G.; Hawley, A.; Clulow, A. J.; Boyd, B. J. Correlating Digestion-Driven Self-Assembly in Milk and Infant Formulas with Changes in Lipid Composition. ACS Appl. Bio Mater. 2020, 3 (5), 3087-3098.
[5] Clulow, A. J.; Salim, M.; Hawley, A.; Boyd, B. J. Milk mimicry – Triglyceride mixtures that mimic lipid structuring during the digestion of bovine and human milk. Food Hydrocolloids 2021, 110, 106126.
