Emulsifying properties

The amphiphilic structures of the main phospholipid molecules result in diverse phase behaviour, particularly in aqueous solutions. At neutral pH the head group of the natural phospholipids may be electrically neutral but zwitter ionic or negatively charged. At lower pH the net negative charge facilitates stronger swelling. 

The enzymatic hydrolysis, acetylation and alcohol fractionation processes all have in common the fact that the zwitter-ion group of the PE is modified or removed. 

There are manifold emulsifying tests, varying from simple laboratory tests to high sophisticated procedures, requiring speciflc apparatus and skills. One may start with the assessment of the emulsifying power of a lecithin in simple empirical tests [26]  

These types of tests can be carried out in a quite simple manner for internal quality control and initial product development. Hence the conditions (mixing time, temperature, stirring equipment, ingredients, time of measurement) should be carefully controlled for obtaining repeatable and reproducible results. Hydrophilic lecithins facilitate the formation of smaller droplets in oil-in-water emulsions. 

More detailed scientific information will require sophisticated equipment, experienced test procedures and skilled scientists. 

---

Deamidation of soy and other seed meal proteins by hydrolysis of the amide bond, and minimization of the hydrolysis of peptide bonds, improves functional properties of these products. For example, treatment of soy protein with dilute (0.05 A/) HCl, with or without a cation-exchange resin (Dowex 50) as a catalyst (133), with anions such as bicarbonate, phosphate, or chloride at pH 8.0 (134), or with peptide glutaminase at pH 7.0 (135), improved solubiHty, whipabiHty, water binding, and emulsifying properties. 

Starch succinates [39316-70-6] are also used as thickening agents in foods. The 1-octenylsuccinate half-ester [52906-93-17, sold as its sodium salt [66829-29-6], has surface active (emulsifying) properties. 

Due to their excellent emulsifying properties, sodium alcohol sulfates are used as emulsifiers for cosmetic creams. In particular, cetylstearyl sulfate in combination with fatty alcohols is used as an emulsifier for ointments. 

The ether carboxylates often have good emulsifying properties. The disadvantage of the polyoxypropylene carboxymethylates is that their biodegradability is worse. 

Already in 1943 M. Schuler [2] described the comparison of the surface-active properties of sodium palmitate with several ether carboxylates based on a constant amount of C atoms. The results showed that with more O bridges the optimal surface activity and emulsifying properties can be achieved at lower temperature, with the detergent properties decreasing and solubility increasing. 

KI Al-Malah, MOJ Azzam, RM Omari. Emulsifying properties of BSA in different vegetable oil emulsions using conductivity technique. Food Hydrocolloids 14 485-490, 2000. 

The tendency of nonionics to produce foam varies. Some, such as the block copolymers, are even used as defoamers. Their wetting, detergency and emulsifying properties also vary widely, depending to a large extent on the balance between the hydrophobic and hydrophilic (oxyethylene) portions. 

Surfactants may exhibit a degree of hydrotropy and thus function as antistatic agents. They are often used for this and for their emulsifying properties in conjunction with fibre lubricants, or may be used alone in a dual capacity as lubricant and antistat. Suitably active surfactants can be found amongst all four ionic types, some typical examples being [471] ... 

For studying the emulsifying properties, saturated polyesters can be used to avoid complications by the reactivity of unsaturated units of the EUP [117]... 

But we must appreciate how the phosphate group acts much like the anion from a weak acid (see Chapter 6), so its exact composition will depend on the pH of solution. The pH of cow s or human milk is about 7 (see Table 6.4). If the pH decreases much below about 6 (e.g. by adding an acid in the form of orange juice), the phosphates become protonated. The emulsifying properties of casein cease as soon as its structure changes, causing the milk to separate. 

FADAs are important ingredients in formulated detergents and cosmetics, since they enhance the emulsifying properties of anionic and... 

Thickening agent. A hydrophilic substance used to increase the viscosity of liquid mixtures and solutions and to aid in maintaining stability of their emulsifying properties. 

The presence of long perfluoroalkyl chains gives sugars surfactant and emulsifier properties, with interesting applications in the biomedical field. These applications... 

Akhtar, M., Dickinson, E. (2003). Emulsifying properties of whey protein-dextran conjugates at low pH and different salt concentrations. Colloids and Surfaces B Biointerfaces, 31, 125-132. 

Dickinson, E., Semenova, M.G. (1992). Emulsifying properties of covalent protein-dex-tran hybrids. Colloids and Surfaces, 64, 299-310. 

Leman, I, Kinsella, J.E. (1989). Surface activity, film formation, and emulsifying properties of milk proteins. Critical Reviews in Food Science and Nutrition, 28, 115-138. 

Galazka, V.B., Dickinson, E., Ledward, D.A. (2000). Emulsifying properties of ovalbumin in mixtures with sulfated polysaccharides effects of pH, ionic strength, heat and high-pressure treatment. Journal of the Science of Food and Agriculture, 80, 1219— 1229. 

Nagasawa, K., Ohgata, K., Takahashi, K., Hattori, M. (1996). Role of the polysaccharide content and net charge on the emulsifying properties of p-lactoglobulin-carboxy-methyldextran conjugates. Journal of Agricultural and Food Chemistry, 44, 2538-2543. 

---