Food Tests (Practicals)

• What is the purpose of the Benedict's test?

  To test for reducing sugars
• What does the buret test identify?

  It identifies proteins in food samples
• What does the iodine test detect?

  It detects starch in food samples
• What is the Sudan 3 test used for?

  To test for lipids in food samples
• What is the emulsion test for lipids?

  A test for lipids using ethanol and water
• What is the procedure to prepare a food sample for testing?

  1. Break food using a mortar and pestle
  2. Add crushed food to distilled water in a beaker
  3. Stir until dissolved
  4. Filter the solution using filter paper
• What temperature should the water bath be set to for the Benedict's test?

  75 degrees Celsius
• What color indicates the presence of reducing sugars in the Benedict's test?

  Green, yellow, or brick red
• What color change occurs in the iodine test if starch is present?

  Changes from browny orange to blue black
• What color change indicates the presence of proteins in the buret test?

  Changes from blue to pink or purple
• How do you perform the Sudan 3 test for lipids?

  Add Sudan 3 stain and shake gently
• What indicates the presence of lipids in the Sudan 3 test?

  A bright red layer at the top
• What is the procedure for the emulsion test for lipids?

  Add ethanol, shake, then add water
• What does a cloudy white color indicate in the emulsion test?

  Presence of lipids in the sample
• What are the common steps in all food tests?

  • Prepare food sample
  • Add specific test solution
  • Observe color change or separation