Skip to main content Accessibility help
×
Home

Heat-induced interactions of β-lactoglobulin A and κ-casein B in a model system

  • Younghee Cho (a1) (a2), Harjinder Singh (a1) and Lawrence K Creamer (a2)

Abstract

The interaction of κ-casein and β-lactoglobulin is fundamental to all heat-induced modifications of milk product functionality, such as the heat stability of concentrated milks. Purified native κ-casein B and β-lg A solutions were heated at 80 °C at pH 6·7 separately and in a mixture. The circular dichroism spectra in the near UV indicated irreversible changes in the disulphide bonding patterns involving both proteins. Alkaline- and SDS-PAGE of heated samples showed that, in the presence of κ-casein, less β-lg was converted into β-lg polymers and the rate of loss of native β-lg was greater. When κ-casein was added to previously heated β-lg and the mixture was heated, the κ-casein reacted with the heat-induced β-lg polymers more readily than with the β-lg native monomers. The formation of β-lg dimers, trimers etc. was diminished. It was concluded that, when β-lg and κ-casein were heated together, β-lg formed thiol-exposed monomers, which reacted with each other or with the native κ-casein depending on the relative concentrations of β-lg and κ-casein. The products of these reactions included some disulphide-bonded 1[ratio ]1 β-lg[ratio ]κ-casein complexes, some monomer κ-casein and a range of large aggregates held together by either or both disulphide bonds and hydrophobic association.

Copyright

Corresponding author

Keywords

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed