Murray, BS and Phisarnchananan, N (2016) Whey protein microgel particles as stabilizers of waxy corn starch + locust bean gum water-in-water emulsions. Food Hydrocolloids, 56. pp. 161-169. ISSN 0268-005X
Abstract
Food-grade whey protein isolate (WPI) microgel particles were investigated as a particle stabilizer of water-in-water (W/W) emulsions. The microgel particles were produced via the novel method of forcing coarse particles of a pre-formed thermally processed WPI protein gel through a jet homogenizer. The Z-average particle size was 149 ± 89 nm but the particles showed a strong tendency for aggregation when the pH was lowered from pH 7 to 4, when the zeta potential also switched from -17 to +12 mV. The viscoelasticity of suspensions of the particles, measured between 1 and 15 vol.% (0.02 and 3 wt.%) increased with concentration and was also higher at pH 4 than pH 7. However, all the suspensions were only weakly shear thinning, suggesting that they did not form very strong networks. The particles were added (at 1-15 vol.%) to a model W/W system consisting of waxy corn starch (S) + locust bean gum (LBG) that normally shows phase separation when the components are mixed at 90 °C then cooled to room temperature (22-25 °C). At 10 to 15 vol.% particles and pH 4, visual observation showed striking inhibition of phase separation, for a period of up to 1 year. Confocal laser scanning microscopy suggested that under these conditions extensive aggregation of the microparticles occurred within the starch phase but also possibly at the W/W interface between the starch-rich and gum-rich regions, supporting a Pickering-type mechanism as responsible for the enhanced stabilization of the W/W emulsion by the microgel particles.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015, Elsevier. This is an author produced version of a paper published in Food Hydrocolloids. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Protein microgel; Pickering; Phase separation; Stabilization |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Food Science and Nutrition (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 15 Jan 2016 13:06 |
Last Modified: | 20 Dec 2016 20:31 |
Published Version: | http://dx.doi.org/10.1016/j.foodhyd.2015.11.032 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.foodhyd.2015.11.032 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:93711 |