iodine for starch

• Required practical 4


  1. Add Benedit's reagent to the food and boil in a water bath

  2. Positive test will fare from blue to brick red
• Test for protein amino acids

  1. Add Baret's reagent to the food

  2. Positive test will go from blue to purple
• Test for fat


  1. Add ethanol to the food and dissolve in water

  2. If present will sit white emulsion
• Test for starch


  Add iodine and will form blue-black if present
• Amylase and starch test

  1. Add a drop of iodine in each well in a spotting tile

  2. Using a water bath, warm amylase and starch and buffer solution

  3. At intervals, take drops of the solution and add into the wells

  4. The starch will break down completely when the solution remains brown
• The time for the starch to break down completely is recorded at 100/time
• The Iodine test for starch

  • Add food sample to a test tube
  • Add a few drops of iodine
  • A sample containing starch will turn blue-black
• • COME
  • FOOD
  • [SAMPLE]
  • POSITIVE
  • RESULT