title: Disposition and crystallization of saturated fatty acid in mixed micelles of relevance to lipid digestion.
abstract: During lipolysis of triglyceride by lipase, monoglyceride and fatty acids are produced which combine with gastrointestinal fluids to form self-assembled structures. These solubilize hydrophobic food components to promote their absorption. The aim of this study was a detailed understanding of structure formation from triglyceride digestion products with saturated short-, medium- and long chain fatty acids. Complementary characterization methods have been applied comprising small angle X-ray and neutron scattering – the latter involving the contrast matching technique using fully deuterated fatty acids – polarized and depolarized dynamic light scattering and cryogenic-transmission electron microscopy. Shape, size and solubilization capacity of the self-assembled structures was dependent on composition and lipid chain length. Crystallization of fatty acid was observed when the solubility limit in the mixed bile salt micelles was exceeded; however, increasing pH and temperature increased the fatty acid solubility. The results provide insight into structure formation and crystallization of incorporated lipolysis products; this is important for a detailed understanding of food structure and nutrition, as well as the rational design of lipid based drug delivery systems.
authors.affiliation: Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Phan
authors.affiliation: Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia. Electronic address: stefan.salentinig@gmail.com.
authors.forename: Stefan
authors.initials: S
authors.lastname: Salentinig
authors.affiliation: Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia.
authors.forename: Elliot
authors.initials: E
authors.lastname: Gilbert
authors.affiliation: National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia.
authors.forename: Tamim A
authors.initials: TA
authors.lastname: Darwish
authors.affiliation: SAXS/WAXS beamline, Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC 3168, Australia.
authors.forename: Adrian
authors.initials: A
authors.lastname: Hawley
authors.affiliation: Centre for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia.
authors.forename: Reece
authors.initials: R
authors.lastname: Nixon-Luke
authors.affiliation: Centre for Molecular and Nanoscale Physics, School of Applied Sciences, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia.
authors.forename: Gary
authors.initials: G
authors.lastname: Bryant
authors.affiliation: Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, VIC 3052, Australia. Electronic address: ben.boyd@monash.edu.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Boyd
mesh_terms: D003460:Crystallization; D016503:Drug Delivery Systems; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008066:Lipolysis; D008823:Micelles; D033363:Neutron Diffraction; D012995:Solubility; D013696:Temperature; D014280:Triglycerides / Q000737:chemistry* / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D005227:Fatty Acids; D008823:Micelles; D014280:Triglycerides
keywords: Cryogenic transmission electron microscopy; Lipid digestion; Lipid-based drug delivery; Lipolysis; Small angle neutron scattering; Synchrotron small angle Xray scattering