Emulsifiers
Pages 77-87
DOI: https://doi.org/10.1094/1891127020.006
ISBN: 1-891127-02-0
Abstract
Topics Covered
- Polysaccharides at Interfaces
- Gums
- Modified Starch
- Cellulose Derivatives
- Salad Dressings
- Pourable Salad Dressings
- Spoonable Salad Dressings
- Mayonnaise
- Reduced-Fat Dressing and Sauces
- Troubleshooting
Introduction to Chapter
Dressings and sauces are a part of traditional cuisines of all types. In terms of interfacial chemistry, they range from the very simple (e.g., an oil and vinegar salad dressing) to the complex (e.g., mayonnaise). A common ingredient is oil, which gives a smooth mouth-feel and extended flavor impact to the food. To function effectively, the oil should be present in a finely divided (i.e., emulsified) state. The means for accomplishing this are many and often involve materials other than (or in addition to) the emulsifiers discussed in Chapter 3. These materials may be proteins (see Chapter 3) or various polysaccharides.
The polysaccharides are often referred to as “stabilizers,” and they work in different ways to maintain the oil in small droplets. Some gums, for example, actually adsorb to the oil-water interface, forming a film with good interfacial viscosity and preventing droplet coalescence. Other polysaccharides inhibit creaming (see Chapter 1) of the emulsified drops by greatly increasing the viscosity of the aqueous phase, while still others prevent creaming by gelling, i.e., forming a semisolid matrix that prevents flotation of the oil drops. Thus, in the strict sense of the word, few of these materials are true “emulsifiers” (surfactants that lower interfacial tension), but they still perform the needed function of stabilizing the dressing or sauce by preventing separation of the oil phase.
