Add the food sample to 2 cm3 of ethanol, shake well. Allow to settle in a test tube rack for 2 minutes for food to dissolve in ethanol. Empty any clear liquid into a testtube containing 2 cm3 of distilled H2O. A MILKY-WHITE EMULSION is a positive result: lipid or fat is present.

Lipids are fatty substances that are organic in nature and do not dissolve in water because of their chemical structure. Lipids are often called fats however lipids canbe either fats or oilsFats are type of lipids that are solid at room temperature and are derived from animals.

Unsaturated fatty acids include monounsaturated and polyunsaturated fatsOils are fats that are liquid at room temperature, like the vegetable oils used in cooking. Solid fats contain more saturated fats and/or trans fats than oils.

The emulsion test is a method to determine the presence of lipids using wet chemistry. The procedure is for the sample to be suspended in ethanol, allowing lipids present to dissolve (lipids are soluble in alcohols). The liquid (alcohol with dissolved fat) is then decanted into water.