title: Blocking Gastric Lipase Adsorption and Displacement Processes with Viscoelastic Biopolymer Adsorption Layers.
abstract: Delayed fat digestion might help to fight obesity. Fat digestion begins in the stomach by adsorption of gastric lipases to oil/water interfaces. In this study we show how biopolymer covered interfaces can act as a physical barrier for recombinant dog gastric lipase (rDGL) adsorption and thus gastric lipolysis. We used β-lactoglobulin (β-lg) and thermosensitive methylated nanocrystalline cellulose (metNCC) as model biopolymers to investigate the role of interfacial fluid dynamics and morphology for interfacial displacement processes by rDGL and polysorbate 20 (P20) under gastric conditions. Moreover, the influence of the combination of the flexible β-lg and the elastic metNCC was studied. The interfaces were investigated combining interfacial techniques, such as pendant drop, interfacial shear and dilatational rheology, and neutron reflectometry. Displacement of biopolymer layers depended mainly on the fluid dynamics and thickness of the layers, both of which were drastically increased by the thermal induced gelation of metNCC at body temperature. Soft, thin β-lg interfaces were almost fully displaced from the interface, whereas the composite β-lg-metNCC layer thermogelled to a thick interfacial layer incorporating β-lg as filler material and therefore resisted higher shear forces than a pure metNCC layer. Hence, with metNCC alone lipolysis by rDGL was inhibited, whereas the layer performance could be increased by the combination with β-lg.
authors.affiliation: Institute of Food Nutrition and Health, ETH Zurich , 8092 Zurich, Switzerland.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Scheuble
authors.affiliation: Institute of Food Nutrition and Health, ETH Zurich , 8092 Zurich, Switzerland.
authors.forename: Micha
authors.initials: M
authors.lastname: Lussi
authors.affiliation: Laboratory of Neutron Scattering and Imaging, Paul Scherrer Institut , 5232 Villigen PSI, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Geue
authors.affiliation: CNRS, Aix Marseille University, UMR7282 Enzymologie Interfaciale et Physiologie de la Lipolyse , Marseille, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Carrière
authors.affiliation: Institute of Food Nutrition and Health, ETH Zurich , 8092 Zurich, Switzerland.
authors.forename: Peter
authors.initials: P
authors.lastname: Fischer
mesh_terms: D000327:Adsorption; D000818:Animals; D001704:Biopolymers / Q000737:chemistry* / Q000494:pharmacology; D004063:Digestion / Q000187:drug effects*; D004285:Dogs; D004548:Elasticity / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry / Q000378:metabolism; D008049:Lipase / Q000037:antagonists & inhibitors / Q000737:chemistry*; D008066:Lipolysis / Q000187:drug effects; D008747:Methylcellulose / Q000737:chemistry; D009765:Obesity / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D012212:Rheology; D013499:Surface Properties / Q000187:drug effects; D014783:Viscosity; D014867:Water / Q000737:chemistry
chemical_list: D001704:Biopolymers; D007782:Lactoglobulins; D008049:Lipase; D008747:Methylcellulose; D014867:Water; C485982:LIPF protein, human