Emulsifiers
Pages 25-45
DOI: https://doi.org/10.1094/1891127020.003
ISBN: 1-891127-02-0
Abstract
Topics Covered
- Emulsifier Types
- Monoglycerides
- Monoglyceride Derivatives
- Sorbitan Derivatives
- Polyhydric Emulsifiers
- Anionic Emulsifiers
- Lecithin
- Hydrophilic/Lipophilic Balance
- Basic Principle of the Concept
- Experimental Determination of HLB
- Proteins
- Foaming Agents
- Emulsifying Agents
- Regulations
Introduction to Chapter
Actual commercial food emulsifiers are seldom exactly like the organic chemical structures that are discussed in this section. Rather, they are mixtures of similar compounds derived from natural raw materials. The hydrophobic fatty acid (or fatty alcohol) chain reflects the nature of the hydrogenated fat or oil used during manufacture. For example, glycerol monostearate (GMS) made from hydrogenated tallow has a saturated fatty acid composition of about 3% C14, 28% C16, 68% C18, and 1% C20, reflecting the chain length distribution in the source fat. If it is made from hydrogenated soybean oil, the chain length distribution is somewhat different (more C18 and less C16). In addition, the ratio of 1-monoglyceride to 2-monoglyceride varies depending on the temperature during manufacture.
Many emulsifiers are the result of rather complex condensation and polymerization reactions. Sorbitan monostearate is made by heating sorbitol and stearic acid together. Sorbitol cyclizes (dehydrates) to a mixture of sorbitans and isosorbides, which in turn is esterified to various extents by the stearic acid. By strict control of reaction conditions, the composition of the final product can be kept in a relatively narrow (and consistent) range, but it is still a mixture.
One should keep in mind, therefore, that the chemical structures shown here represent the major components in the commercial material and that related molecular species are also present.
