Tuning heat-­‐induced colloidal aggregation of whey proteins, sodium caseinate and gum arabic: effect of protein composition, preheating and gum arabic level

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Date
2014
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ELSEVIER SCI LTD
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Abstract
Heating can drive the colloidal complexation of negatively-­‐charged proteins and polysaccharides by strengthening hydrophobic interactions and denaturing proteins, thereby exposing reactive sites for covalent and noncovalent bonding. We have previously shown that stable colloidal aggregates comprising whey protein, sodium caseinate and gum arabic can be produced by careful selection of heat treatment, pH and protein type. Here we tested how the size, composition, charge and morphology of colloidal aggregates are affected by the amounts of whey protein, sodium caseinate and gum arabic, as well as the thermal history of the proteins. Increasing amounts of whey protein resulted in larger particles, which were more prone to precipitate. Preheating whey protein slightly enhanced aggregation, and this effect was mitigated when sodium caseinate was present during preheating (chaperone effect). Increasing amounts of gum arabic produced larger particles with less charge, but the gum arabic effect was statistically confounded with ionic strength. We believe that both covalent (disulphide) and noncovalent interactions among protein molecules are required to overcome electrostatic repulsion at pH 7 and form stable aggregates.
Description
NOTICE: this is the author’s version of a work that was accepted for publication in Food Research International. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Food Research International, 62,(2014) http://dx.doi.org/10.1016/j.foodres.2014.02.018
Keywords
Colloidal aggregation, Whey protein, Casein, Gum arabic, Heating, Disulfide bonding
Citation
Loveday, S. M., A. Ye, et al. (2014). "Tuning heat-­‐induced colloidal aggregation of whey proteins, sodium caseinate and gum arabic: Effect of protein composition, preheating and gum arabic level." Food Research International 62: 128-­‐136.
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