B2 - food tests

• Benedict test to test for sugars:

  1. prepare food sample and transfer 5cm into test tube
  2. prepare water bath to 75 degrees
  3. add 10 drops of Benedict's soltuion using pipette
  4. place test tube into water bath and leave for 5 mins
  5. if sample contains reducing sugar, solution changesfrom blue to green, yellow or brick red
• iodine solution to test for starch:

  1. prepare food sample and transfer 5cm to test tube
  2. add drops of iodine solution and shake tube
  3. if starch present, colour changes from orange to blue/black
• buiret test for protein:

  1. prepare food sample and transfer 2cm to test tube
  2. add 2cm of buiret to sample and shake
  3. if protein present, solution will change from blue to purple
• sudan III test for lipids:

  1. prepare food sample and transfer 5cm to test tube
  2. use pipette to add 3 drops of solution to tube and shake
  3. if lipids present, mixture will seperate into two layers - top layer will be bright red