Influence of Small Amphiphiles on Aqueous Dispersions of <i>β</i>-Lactoglobulin A and Bovine Serum Albumin: (2) Surface Energy and Emulsifying Properties

Abstract

Influence of amphiphiles on surface energy ( γ ), emulsifying activity index (EAI) and emulsion stability (ES) of fatty-acid free bovine serum albumin (FAF-BSA), bovine serum albumin (BSA), and β-lactoglobulin A ( β -LGA) was studied. Contact angle measurements ( θ ) of sessile drops of protein-surfactant mixtures were determined using water and α-bromonaphthalene as solvents of known parameters to calculate γ . All surfactants except zwitterionic Z8 increased γ . The greatest increase was by anionic SDS. All surfactants significantly reduced EAI in spite of increased γ . ES was reduced by all surfactants except cationic TDTM which, conversely, enhanced ES by up to 186% for BSA and β -LGA.