Overview of Food Emulsifiers

Food colloids, emulsions and foams have their origins in nature and have evolved with advances in food processing techniques. Milk, for example, has a naturally occurring membrane, which allows solid fat to be dispersed into an aqueous phase. Early food formulations for butter, cheese, whipped cream and ice cream took advantage of these natural emulsifiers. The invention of mayonnaise as a cold sauce in France utilizes egg lipoproteins and phospholipids to disperse oil into an acidified aqueous phase. The emulsifying power of these lipoproteins is still impressive by today’s standards, because up to 80% oil could be dispersed without inversion to an oil continuous emulsion. In 1889, the French chemist Hippolyte Mege- Mouries invented margarine as a low-cost substitute for butter. An aqueous phase was dispersed into a molten tallow to form an oil continuous emulsion. Subsequent discovery of the hydrogenation process allowed the substitution of partially hydrogenated oil for the tallow. In this application, the emulsion only had to be stable long enough to solidify the fat and fill into containers.

Synthetic emulsifiers have only come into wide commercial use in the second half of the twentieth century. Their development was driven by the processed food industry, which needed shelf-stable products for distribution through mass-market channels. For example, creamy salad dressings may be stored for up to a year without visible separation. Other factors, such as rancidity, are now more important factors in predicting product stability.

The science of food emulsions has been extensively covered by other authors (Dickinson and Rodriguez-Patino, 1999; Friberg et al., 2003; McClements 2004). This book will concentrate on the structure, preparation, analysis, interactions, and applications of emulsifiers.