Foams and emulsions stabilization

The complex interfacial dilational modulus ( ) is a key fundamental property governing foam and emulsion stability. It is defined as the interfacial tension increment (da) per unit fractional interfacial area change (dA/A) i.e.,... 

Hartamide. [Hart Chem. Ltd.] Fatty acid alkanolamides couiding agent detergent foam and emulsion stabilizer, vise, regulator, lubricant antistat for doeigents and cosmetics. 

Limited enzyme treatment significantly reduced the viscosity of concentrated protein solutions and emulsification capacities were increased (5 ). The enzyme-treated proteins had slightly increased water absorption and foaming properties, but foam and emulsion stabilities were decreased (54). 

The interfacial rheology of protein adsorption layers has been intensively studied in relation to the properties of foams and emulsions stabilized by proteins and their mixtures with lipids or surfactants. Detailed information on the investigated systems, experimental techniques, and theoretical models can be found in Refs. [762-769]. The shear rheology of the adsorption layers of many proteins follows the viscoelastic thixotropic model [770-772], in which the surface shear elasticity and viscosity depend on the surface shear rate. The surface rheology of saponin adsorption layers has been investigated in Ref. [773]. 

A. R. Studart, U. T. Gonzenbach, I. Akartuna, E. Tervoort, and L. J. Gauckler, "Materials from foams and emulsions stabilized by colloidal particles," J. Mater. Chem.,... 

Hailing, P.J., Protein Stabilized Foams and Emulsions, CRC Critical Reviews in Food Science And Nutrition, 155 (1981). 

Clark, D.C., Mackie, A.R., Wilde, P.J., Wilson, D.R. (1994). Differences in the structure and dynamics of the adsorbed layers in protein-stabilized model foams and emulsions. 

We have used film interferometry to reveal a new mechanism for the stabilization of foams and emulsions due to layering inside the thinning films, as will be discussed below. 

There are also several water-soluble mixtures of polysaccharides, including those derived from seaweeds and marine animals, such as gum arabic, agar, algin, carrageenan, and chitin. These are hydrophilic. Their suspensions in water can be quite viscous and can readily form gels, and they can form viscous interfacial films around dispersed droplets and bubbles [821], They are used to stabilize suspensions, foams, and emulsions and are used in many different foods and medicines including, for example, ice cream [428,430], See also Ref. [822],... 

Damodaran, S. Protein-Stabilized Foams and Emulsions in Food Proteins and Their Applications, Damodaran, S. Paraf, A. (Eds.), Dekker, New York, 1997, pp. 57-110. 

Hailing, P.J. 1981. Protein-stabilized foams and emulsions. CRC Crit. Rev. Food Sci. Nutr. 15,155-203. 

Succinyl- ation Increased solubility at acidic pH, increased tolerance to Ca +, good foam capacity, stability, emulsifying activity and emulsion stability. More resistance to aggregation. Lowered viscosity (12)... 

Although whey protein concentrates possess excellent nutritional and organoleptic properties, they often exhibit only partial solubility and do not function as well as the caseinates for stabilizing aqueous foams and emulsions (19). A number of compositional and processing factors are involved which alter the ability of whey protein concentrates to function in such food formulations. These include pH, redox potential, Ca concentration, heat denaturation, enzymatic modification, residual polyphosphate or other polyvalent ion precipitating agents, residual milk lipids/phospholipids and chemical emulsifiers (22). 

It is likely that the inability of whey proteins to function as well as caseinate in stabilizing foams and emulsions is due to conformational and structional differences in the two proteins. 

Since t(Q data for the emulsion bilayers are rather scattered, only Ce and % could be estimated Ce = 0.5 - 3-103 mol dm 3, % = 610"12 J m1. From the comparison of the t(C) dependences for the foam and emulsion bilayers in Fig. 3.92 it is seen that the stability of the foam bilayers is greater than that of the emulsion bilayers and that Ce is much lower for the... 

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