Formulation of pickering emulsions and investigating the intragastric gelation behavior using flow-assisted mri

Date

2025-9-01

Author

İlhan, Esmanur

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

224
views

0
downloads

Cite This

Intragastric gelation, which delays gastric emptying by forming gel-like networks under gastric conditions, is recognized as a potential strategy for controlling food digestion and satiety. Pickering emulsions, stabilized by protein–polysaccharide complexes, provide a versatile platform for designing such systems because particles irreversibly anchor to droplet surfaces and can tailor interfacial architecture. Motivated by this potential, this dissertation aimed to formulate Pickering emulsions capable of intragastric gelation and to employ them as a model system for the advancement of a benchtop-compatible Flow Assisted Magnetic Resonance Imaging (Flow-MRI) methodology to investigate their structural evolution and gastrointestinal response. System optimization was conducted through case studies addressing laminar flow, pulsation damping, gravity-driven flow, and pressure calibration, ensuring reproducible velocity profiles and enabling Flow-MRI integration with digestion studies. Particles were characterized by FTIR, TD-NMR, water-holding capacity WHC, and oil adsorption OA, while emulsions were evaluated by particle size, microscopy, TD-NMR, and rheometry. Flow-MRI, applied in parallel with conventional rheology, provided velocity fields and viscosity distributions with spatial resolution. This comparative approach demonstrated how Flow-MRI extends bulk rheology by capturing digestion-induced heterogeneities and offering complementary insight into digestion-induced transformations. Results indicated that the polysaccharide-to-protein (PS:PR) ratio governed the extent of particle complexation and branching, thereby influencing the availability of binding sites and altering both emulsion stability and digestive behavior. The type of protein further modulated gelation pathways, leading either to continuous bulk-like gel matrices or to phase-separated systems characterized by dispersed particulate gels. Flow-MRI complemented rheology by capturing plug-like flow, wall slip, and heterogeneous viscosity distributions, emphasizing the role of spatially resolved analysis in distinguishing these distinct gelation modes. Collectively, this work establishes Flow-MRI as a robust and complementary tool to conventional methods, advancing mechanistic understanding of how protein–polysaccharide particles govern emulsion digestion. Beyond methodological innovation, the outcomes provide practical guidance for the rational design of functional emulsions with tailored stability, controlled digestion, and nutritional applications.

Subject Keywords

Intragastric gelation, Flow-MRI, Pickering Particle, Emulsion

URI

https://hdl.handle.net/11511/116077

Collections

Graduate School of Natural and Applied Sciences, Thesis