Properties of sodium caseinate as affected by the β-casein phenotypes.

Autor: Daniloski D; Victoria University, Advanced Food Systems Research Unit, Institute for Sustainable Industries and Liveable Cities and College of Health and Biomedicine, Melbourne, Victoria 8001, Australia; Teagasc Food Research Centre, Food Chemistry and Technology Department, Moorepark, Fermoy, P61 C996, Cork, Ireland., McCarthy NA; Teagasc Food Research Centre, Food Chemistry and Technology Department, Moorepark, Fermoy, P61 C996, Cork, Ireland., Auldist MJ; Agriculture Victoria, Department of Jobs, Precincts and Regions, Ellinbank, Victoria 3821, Australia; University of Melbourne, Centre for Agricultural Innovation, School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, Melbourne, Victoria 3010, Australia., Vasiljevic T; Victoria University, Advanced Food Systems Research Unit, Institute for Sustainable Industries and Liveable Cities and College of Health and Biomedicine, Melbourne, Victoria 8001, Australia. Electronic address: todor.vasiljevic@vu.edu.au.
Jazyk: angličtina
Zdroj: Journal of colloid and interface science [J Colloid Interface Sci] 2022 Nov 15; Vol. 626, pp. 939-950. Date of Electronic Publication: 2022 Jul 06.
DOI: 10.1016/j.jcis.2022.07.021
Abstrakt: The aim of the study was to investigate the properties of sodium caseinate dispersions and oil-in-water emulsions obtained from cows' milk of either A1/A1, A1/A2, or A2/A2 β-casein phenotype. Protein structural characterisation was examined using Fourier Transform Infrared and Nuclear Magnetic Resonance spectroscopies, with physicochemical and interfacial properties assessed by analysing adsorbed protein content, hydrophobicity, solubility, and emulsion stability of the samples. Results showed variations in the secondary structure of all samples dependent of the presence of A1 or A2 β-caseins. The main differences included greater amounts of α-helix and β-sheet in A1/A1 and A1/A2 sodium caseinate dispersions that influenced their lower solubility, while random coils/polyproline II helixes were found only in A2/A2 sodium caseinate dispersion. In contrast, upon adsorption on the interface of A2/A2 sodium caseinate emulsion, the protein adopted ordered conformational motifs. This conformational shift supposedly arose from structural differences between the two β-casein proteoforms, which most likely enhanced the emulsion properties of A2/A2 sodium caseinate compared to either A1/A1 or A1/A2 sodium caseinates. The A2 β-casein in both, A1/A2 and A2/A2 sodium caseinates, appears to be able to more rapidly reach the oil droplet surface and was more efficient as emulsifying agent. The current results demonstrated that the conformational rearrangement of proteins upon adsorption to emulsion interfaces was dependent not only on hydrophobicity and on solubility, but also on the conformational flexibility of A1/A1, A1/A2, and A2/A2 β-casein phenotypes. These findings can assist in predicting the behaviour of sodium caseinates during relevant industrial processing.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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