Implications of interfacial characteristics of food foaming agents in foam formulations.

The manufacture of food dispersions (emulsions and foams) with specific quality attributes depends on the selection of the most appropriate raw materials and processing conditions. These dispersions being thermodynamically unstable require the use of emulsifiers (proteins, lipids, phospholipids, surfactants etc.).

Structural and shear characteristics of adsorbed sodium caseinate and monoglyceride mixed monolayers at the air-water interface.

The structural and shear characteristics of mixed monolayers formed by an adsorbed Na-caseinate film and a spread monoglyceride (monopalmitin or monoolein) on the previously adsorbed protein film have been analyzed. Measurements of the surface pressure (pi)-area (A) isotherm and surface shear viscosity (eta(s)) were obtained at 20 degrees C and at pH 7 in a modified Wilhelmy-type film balance. The structural and shear characteristics of the mixed films depend on the surface pressure and on the composition of the mixed film.

Structure, miscibility, and rheological characteristics of beta-casein-monoglyceride mixed films at the air-water interface.

In this work we have used different and complementary interfacial techniques (surface film balance, Brewster angle microscopy, and interfacial dilatational rheology) to analyze the static (structure, morphology, reflectivity, miscibility, and interactions) and dynamic characteristics (surface dilatational properties) of beta-casein and monoglyceride (monopalmitin and monoolein) mixed films spread on the air-water interface. The static and dynamic characteristics of the mixed films depend on the interfacial composition and the surface pressure. At higher surface pressures, collapsed beta-casein residues may be displaced from the interface by monoglyceride molecules with important repercussions on the interfacial characteristics of the mixed films.

The Effect of pH on Monoglyceride-Caseinate Mixed Monolayers at the Air-Water Interface.

The surface pressure (pi) area (A) isotherms and Brewster angle microscopy (BAM) of monoglyceride-caseinate mixed films spread on buffered water at pH 5 and 7 and at 20 degrees C were determined as a function of the mass fraction (X) of monoglyceride (monopalmitin or monoolein) in the mixture. The structural characteristics, miscibility, and morphology of monoglyceride-caseinate mixed films are very dependent on surface pressure and monolayer composition. The monolayer structure was more expanded as the pH and the monoglyceride concentration in the mixture were increased.