food tests

• How do you prepare a food solution?

  1. Crush the food using a pestle and mortar

  2.Add a few drops of distilled water and mix well
• how to test for starch

  1. Add a few drops of iodine solution(iodine solution is an orange-yellow liquid)

  2.If the solution turns a dark blue-black colour the food contains starch!
• How to test for lipids in a solid piece of food

  You have to use a piece of filter paper to test for lipids in a solid piece of food.

  1.Rub some of the food onto a piece of filter paper.

  2.Hold the paper up to the light.If the paper goes translucent it contains lipids.
• To test for lipids in a food solution

  You use ethanol which is a colourless liquid

  1. Add a few drops of ethanol to the food solution

  2.Shake the test tube and leave for one minute

  3.Pour the ethanol into a test tube of water

  4.If the solution turns cloudy,the food contains lipids.
• How do you test for sugar?

  1. Add a few drops of Benedict's solution to food solution.

  2. Heat test tube in water bath.

  3. If solution turns orange-red, the food contains sugar
• How do you test for protein?

  1. add a few drops of copper sulfate

  2. add a few drops of sodium hydroxide

  3. if it is purple - it contains protein