Soy and meat proteins as emulsion stabilizers. 4. The stability and interfacial rheology of O/W emulsions stabilised by soy and meat protein fractions

Abstract

Globular soy (7S, 11S and acid precipitated) and water-soluble meat protein (WSMP) fractions form interfacial films at the corn oil—water interface that are more viscoelastic than films formes by non-globular salt—soluble meat proteins (SSMP). The concentration of adsorbed protein in films of globular protein fractions is also higher than for non-globular protein fractions. A close correlation was observed between the rate of drop coalescence in corn oil-in-water emulsions stabilised by the various protein fractions and the instantaneous surface elastic modulus (E o(S)) of the interfacial films. Drop coalescence decreased as E o(S) increased. WSMP gave more stable emulsions than soy protein fractions or SSMP, pH and NaCl have a substantial influence on molecular conformation in solution and, consequently, on interfacial adsorption and rheology, and also on emulsion stability.