food tests

• starch test

  iodine orange-brown

  turns blue- black
• protein test

  biuret test- blue

  potassium hydroxide

  copper sulphate

  turns mauve/ purple in protein
• reducing sugars test

  benedicts solution- blue

  turns orange/red

  sucrose doesnt react to benedicts solution
• lipids test

  emulsion test - initially colourless

  ethanol

  distilled water

  turns milky white in lipids