Rp food test

• What should you be able to describe by the end of the video?

  How to carry out chemical tests
• What is the focus of the required practical mentioned?

  The chemical tests for carbohydrates, proteins, and lipids
• What must be worn due to the hazardous nature of the chemicals?

  Safety goggles
• What is the procedure for preparing a food sample for testing?

  1. Grind food sample with distilled water using a mortar and pestle.
  2. Transfer paste to a beaker and add more distilled water.
  3. Stir to dissolve chemicals and food.
  4. Filter to remove suspended food particles.
• What are the two main types of carbohydrates mentioned?

  Starch and sugars
• How do you test for starch in a food sample?

  Add iodine solution to the food solution
• What color does iodine turn if starch is present?

  Blue-black
• What color does iodine remain if no starch is present?

  Orange
• How do you test for sugars like glucose?

  Add Benedict solution and heat in water
• What color indicates a small amount of sugar in the Benedict test?

  Green
• What does a brick red color in the Benedict test indicate?

  A lot of sugar is present
• What type of sugars does the Benedict test work for?

  Reducing sugars
• What is the test for proteins?

  Add Biuret solution to the food solution
• What color change indicates the presence of protein in the Biuret test?

  Blue to purple or lilac
• What is the procedure for testing lipids?

  1. Grind food with distilled water using a mortar and pestle.
  2. Transfer to a test tube without filtering.
  3. Add distilled water and ethanol.
  4. Gently shake the solution.
  5. Look for a white cloudy emulsion.
• What indicates the presence of lipids in the test?

  A white cloudy emulsion forms
• Why do we not filter the solution when testing for lipids?

  Lipid molecules can stick to filter paper
• What is a safety concern when using ethanol in lipid testing?

  Ethanol is highly flammable
• What are the key chemicals used in the tests for carbohydrates, proteins, and lipids?

  • Carbohydrates: Iodine solution, Benedict solution
  • Proteins: Biuret solution
  • Lipids: Ethanol, distilled water
• Where can you find more questions on testing for chemicals in foods?

  In the vision workbook