Meaning
Lipids can be tested for with different methods.
The Paper Test Method
- 1. Take a small sample of food.
- 2. Wipe it on a piece of paper.
- 3. Hold the paper up to the light.
- 4. If the paper has turned translucent the food contained lipids.
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| There are two patches where fat has been asborbed by the paper.
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The Alcohol Emulsion Test Method
- 1. Take a small sample of food.
- 2. Place the food in ethanol and mix by shaking or stirring.
- 3. Filter the mixture.
- 4. Add the clear solution to some water.
- 5. If lipids are present then a white emulsion will appear.
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| The mixture on the right shows the presence of lipids.
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The Sudan III Test Method
- 1. Mix a small amount of the food sample with water in a test tube.
- 2. Add a few drops of Sudan III dye to the test tube and mix.
- 3. If lipids are present, a red-stained oil layer will form on the surface of the water.
- 4. If no red-stained oil layer forms, the food sample likely does not contain fats.
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| The mixture shows the SudanIII has turned red in the presence of lipids.
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