Emulsifying and Structural Properties of β-Lactoglobulin at Different PHs

Abstract

The emulsifying properties of β-lactoglobulin (β-Lg) in relation to its molecular structure were investigated at pH 3~9. In the acidic pH region, β-Lg showed relatively low emulsifying and surface activity, while its surface hydrophobicity was greater than at neutral pHs. The conformational stability of β-Lg varied depending on pH, i.e. its conformation was more rigid and resistant to denaturation at pH 3 than at pH 7. The low emulsifying and surface activity of β-Lg at acidic pHs was assumed to be due to such low denaturability (flexibility) of the molecule. Cleavage of the intramolecular disulfide bonds increased the denaturability, as well as the emulsifying activity, of β-Lg at pH 3. © 1985, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.