Food tests

• starch is a


  complex carbohydrate made of glucose molecules
• Test for starch


  Iodine solution

  •grind up food to increase surface area

  •put solution on food

  -Positive:Blue black (starch present)

  -Negative:Orange yellow
• STARCH TEST?


  IODINE SOLUTION
• Glucose is a


  Carbohydrate and simple sugar
• SUGAR TEST


  BENEDICT'S SOLUTION
• Sugar test


  •grind up food to increase surface area

  •add blue Benedict's solution

  •heat the solution

  -turns BRICK RED -> sugar is present
• PROTEIN TEST


  BUIRET SOLUTION
• protein test:


  •grind up food to increase surface area

  •add blue buiret solution to food being tested

  -if it turns PURPLE -> protein PRESENT
• LIPIDS TEST


  ETHANOL (emulsion test)
• Lipids test:


  •grind up food to increase surface area

  •add CLEAR ethanol to food being tested

  -CLOUDY WHITE LAYER-> lipids present
• Hazard with ethanol/emulsion tests


  Ethanol is highly flammable and harmful