The sol-gel-sol transformation behavior of egg white proteins induced by alkali

In the current study, we found an interesting phenomenon that fresh egg white (EW) undergo the sol-gel-sol transition with alkali treatment. The transformation behavior at different alkalinity (1.5%, 2.0%, and 2.5%) was investigated. As the gel formed, the hardness, lightness, surface hydrophobicity...

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Bibliographic Details
Published in:International journal of biological macromolecules 2020-07, Vol.155, p.588-597
Main Authors: Gao, Xuejing, Yao, Yao, Wu, Na, Xu, Mingsheng, Zhao, Yan, Tu, Yonggang
Format: Article
Language:English
Subjects:
Alkali
Alkalies - chemistry
Animals
Ducks
Egg Proteins - chemistry
Egg white
Egg White - chemistry
Gelation
Gels - chemistry
Hydrophobic and Hydrophilic Interactions
Phase Transition
Rheology
Sol-gel-sol
Transformation behavior
Viscosity
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Summary:In the current study, we found an interesting phenomenon that fresh egg white (EW) undergo the sol-gel-sol transition with alkali treatment. The transformation behavior at different alkalinity (1.5%, 2.0%, and 2.5%) was investigated. As the gel formed, the hardness, lightness, surface hydrophobicity and the total number of identified peptides increased, and then, remarkable reduction when the gel collapsed. Rheological behavior indicated that the viscosity varied with shear rate. Fourier transform infrared spectroscopy (FTIR) showed that β-sheets gradually decreased as the α-helices increased during gel-sol transformation. The quantification of EW peptides analysis revealed that there was no dramatic correlation between the number of identified peptides and alkalinity. It was concluded that the sol-gel-sol transition was strongly dependent on alkali levels, moreover, high concentration promoted gel formation as well as liquefaction. The EW transformation behavior induced by alkali had a significant effect on protein aggregation and denaturation, and further changed physicochemical properties. [Display omitted] •Egg white proteins undergo the sol-gel-sol transformation with alkali treatment.•Alkali changes not only the appearance of EW, but also the protein structure.•The ionic bonds increase and the disulfide bonds reduce during gel liquefaction.•Alkaline degradation of EW proteins gel lacks sufficient specific cleavage sites.•Low concentration of alkali keeps the gel more stable than high concentration.
ISSN:0141-8130
1879-0003
DOI:10.1016/j.ijbiomac.2020.03.209