Thickening a liquid with long food molecules Dissolved molecules of plant starch or animal gelatin get tangled up with each other and impede the flow of the liquid Emulsions: Thickening with Droplets Thanks to their very different structures and properties, water molecules and oil molecules don’t mix evenly with each other(p 797) Neither can dissolve in the other If we use a whisk or blender to force a small portion of oil to mix into a larger one of water, the two form a milky, thick fluid Both the milkiness and the thickness are caused by small droplets of oil, which block light rays and the free movement of water molecules The oil droplets thus behave much as the solid particles in a suspension do Such a mixture of two incompatible liquids, with droplets of one liquid dispersed in a continuous phase of the other, is called an emulsion The term comes from the Latin word for “milk,” which is just such a mixture (p 17) Emulsifiers In addition to the two incompatible liquids, a successful emulsion requires a third ingredient: an emulsifier An emulsifier is a substance of some kind that coats the oil droplets and prevents them from coalescing with each other Several different materials can serve this function, including proteins, cell-wall fragments, and a group of hybrid molecules (for example, egg-yolk lecithin) that have an oil-like end and a watersoluble end (p 802) To make an emulsified sauce, we add oil to a mixture of water and emulsifiers (egg yolk, ground herbs or spices), and break the oil up into microscopic droplets, which the emulsifiers immediately coat and stabilize Or we can begin with a premade ...two incompatible liquids, with droplets of one liquid dispersed in a continuous phase of the other, is called an emulsion The term comes from the Latin word for “milk,” which is just such a mixture (p 17) Emulsifiers In addition... lecithin) that have an oil-like end and a watersoluble end (p 802) To make an emulsified sauce, we add oil to a mixture of water and emulsifiers (egg yolk, ground herbs or spices), and break the oil up into microscopic droplets, which the emulsifiers... other Several different materials can serve this function, including proteins, cell-wall fragments, and a group of hybrid molecules (for example, egg-yolk lecithin) that have an oil-like end and a watersoluble