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Lipid Emulsions
D. Julian McClements and Jochen Weiss
University of Massachusetts
Amherst, Massachusetts

1. INTRODUCTION
Many natural and processed foods contain small droplets of oil dispersed in an aqueous medium (e.g., milk, cream, fruit beverages, soups, cake batters, mayonnaise, cream liqueurs, sauces, deserts, salad cream, and ice cream) or small droplets of water dispersed in a lipid medium (e.g., butter and margarine). Despite the considerable diversity of physicochemical and sensory characteristics exhibited by these foods, they can all be considered to fall into a class of material called ‘‘emulsions’’ and their properties can be understood using the concepts and techniques of ‘‘emulsion science’’ (1–4). Emulsion science is a multidisciplinary subject that combines chemistry, physics, and engineering (5–12). The objective of emulsion scientists working within the food industry is to use the principles and techniques of emulsion science to improve the quality of the food supply and the efficiency of food production. The purpose of this chapter is to introduce the basic principles and techniques of emulsion science that are relevant for understanding, characterizing, and manipulating the properties of food products.
The wide diversity of physicochemical and organoleptic characteristics exhibited by food emulsions is the result of product formulation and processing conditions used to create them. The manufacture of an emulsion-based food product with specific desirable quality attributes depends on the selection of the suitable raw

Bailey’s Industrial Oil and Fat Products, Sixth Edition, Six Volume Set.
Edited by Fereidoon Shahidi. Copyright # 2005 John Wiley & Sons, Inc.

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materials (e.g., water, oil, emulsifiers, thickening agents, minerals, acids, bases, vitamins, flavors, colorants, etc.) and