However, oil and water cannot mix without help. The enabler generally occurs in the form of emulsifier ingredients that assist in getting two immiscible liquids to mix and stay mixed. According to the Lipid Glossary 2 (2000, eds. Gunstone, FD and Herslof, BG, The Oily Press), an emulsifier is defined as “a surface-active compound which promotes the formation of emulsions between water and fatty or oily compounds. Important in cleaning processes and also in many foods.”
The glossary goes further: “a variety of emulsions exist in food. Examples include margarine, butter, and mayonnaise (semi-solid; water-in-oil emulsions), milk and dressings (liquid; oil-in-water emulsions) and ice cream (mixture).”