The emulsion test is a test done to show the presence or absence of lipids in a substance. In this test the substance is first dissolved in alcohol. This solution is then dissolved in water. If lipids are present in the mixture then it will precipitate and the hydrophilic head will surround the hydrophobic tails forming an emulsion.
The emulsion test, test for fats/oils in foods by breaking down the lipids. The food is placed in ethanol and a bit of water