Sarkar, A orcid.org/0000-0003-1742-2122, Zhang, S, Murray, B orcid.org/0000-0002-6493-1547 et al. (2 more authors) (2017) Modulating in vitro gastric digestion of emulsions using composite whey protein–cellulose nanocrystal interfaces. Colloids and Surfaces B: Biointerfaces, 158. pp. 137-146. ISSN 0927-7765
Abstract
In this study, we designed emulsions with an oil-water interface consisting of a composite layer of whey protein isolate (WPI, 1 wt%) and cellulose nanocrystals (CNCs) (1–3 wt%). The hypothesis was that a secondary layer of CNCs at the WPI-stabilized oil-water interface could protect the interfacial protein layer against in vitro gastric digestion by pepsin at 37 °C. A combination of transmission electron microscopy, ζ-potential measurements, interfacial shear viscosity measurements and theoretical surface coverage considerations suggested the presence of CNCs and WPI together at the O/W interface, owing to the electrostatic attraction between complementarily charged WPI and CNCs at pH 3. Microstructural analysis and droplet sizing revealed that the presence of CNCs increased the resistance of the interfacial protein film to rupture by pepsin, thus inhibiting droplet coalescence in the gastric phase, which occurs rapidly in an emulsion stabilized by WPI alone. It appeared that there was an optimum concentration of CNCs at the interface for such barrier effects. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) results further confirmed that the presence of 3 wt% of CNCs reduced the rate and extent of proteolysis of protein at the interface. Besides, evidence of adsorption of CNCs to the protein-coated droplets to form more rigid layers, there is also the possibility that network formation by the CNCs in the bulk (continuous) phase reduced the kinetics of proteolysis. Nevertheless, structuring emulsions with mixed protein-particle layers could be an effective strategy to tune and control interfacial barrier properties during gastric passage of emulsions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2017, Elsevier B.V. All rights reserved. This is an author produced version of a paper published in Colloids and Surfaces B: Biointerfaces. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Cellulose nanocrystals; Emulsion; In vitro gastric digestion; Particle-protein interface; Whey protein; Pepsin |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Biological Sciences (Leeds) > School of Molecular and Cellular Biology (Leeds) > Cell Biology (Leeds) The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 29 Jun 2017 16:19 |
Last Modified: | 23 Jun 2018 00:38 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.colsurfb.2017.06.037 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:118424 |