food test

• What are the different food tests covered in the video?

  The Benedict's test, iodine test, Buret test, and Sudan 3 test
• What is the purpose of the Benedict's test?


  It tests for reducing sugars
• What is the iodine test used for?


  It is used to test for starch
• What does the Buret test detect?


  It detects proteins
• What does the Sudan 3 test identify?


  It identifies lipids
• What is the first step in preparing a food sample for testing?


  Break it up using a mortar and pestle
• What should you do after crushing the food sample?


  Add it to a beaker with distilled water and stir
• Why do you filter the solution after preparing the food sample?


  To remove solid bits of food
• What are the two types of sugars mentioned?

  Reducing sugars and non-reducing sugars
• What is the temperature of the water bath for the Benedict's test?


  75 degrees Celsius
• How do you know if reducing sugars are present in the Benedict's test?


  The solution changes from blue to green, yellow, or brick red
• What color does the iodine solution turn if starch is present?


  Blue-black
• How much of the food sample is needed for the Buret test?


  2 centimeters cubed
• What color change indicates the presence of protein in the Buret test?


  The solution changes from blue to pink or purple
• What is the first step in the Sudan 3 test?


  Add three drops of Sudan 3 stain solution
• What indicates the presence of lipids in the Sudan 3 test?


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


  Add two centimeters cubed of ethanol and shake vigorously
• What does a cloudy white color indicate in the emulsion test?


  It indicates that lipids were present
• What are the steps to prepare a food sample for testing?

  1. Break the food using a mortar and pestle.
  2. Add the crushed food to a beaker with distilled water and stir.
  3. Filter the solution using a funnel lined with filter paper.
• What are the common characteristics of the food tests mentioned?

  • Each test requires a prepared food sample.
  • Tests include Benedict's for sugars, iodine for starch, Buret for proteins, and Sudan 3 for lipids.
  • The emulsion test is specific for Edexcel course students.
• Compare the tests for sugars and starch.

  • Benedict's test:
  • Tests for reducing sugars.
  • Color change from blue to green/yellow/brick red.

  
  

  • Iodine test:
  • Tests for starch.
  • Color change from browny orange to blue-black.
• Compare the Buret test and the Sudan 3 test.


  • Buret test:
  • Tests for proteins.
  • Color change from blue to pink/purple.

  
  

  • Sudan 3 test:
  • Tests for lipids.
  • Bright red layer indicates presence of lipids.
• What are the safety precautions for the Benedict's test?


  • Use a test tube holder to place the test tube in the water bath.
  • Point the test tube away from yourself and others.