Biochemical Tests

• test for starch?


  add iodine reagent (orange)

  if starch is present then the solution turns from orange to blue-black
• test for reducing-sugar?

  add benedicts reagent (blue)

  heat by placing the test tube in a beaker filled with hot water

  green/yellow means small amount of reducing sugar present

  brick-red means a lot of reducing sugar present
• test for non-reducing sugar?

  add benedicts reagent (blue)

  add dilute hydrochloric acid and boil

  then neutralise it by adding sodium hydrogen carbonate

  add benedicts reagent and heat again

  green/yellow means small amount of non-reducing sugar present

  brick-red means a lot of non-reducing sugar present
• test for lipid?


  add ethanol and shake

  then add water

  a cloudy, white emulsion forms if lipids are present