Food Test Biology

Question 1

Starch

Answer 1

Test: Iodine.

Clout at start: Amber

Colour at end of positive test: Blue/Black

Question 2

Reducing Sugar

Answer 2

Test: Benedict’s (plus heat)

Colour at start: Blue

Colour at end: Brick-red (a little sugar-green)

Question 3

Lipids

Answer 3

Test: Emulsion (ethanol)

Colour at start: Clear

Colour at end: Milky emulsion (droplets suspended)

Question 4

Protein

Answer 4

Test: Biuret test (potassium hydroxide copper sulphate)

Colour at start: No change

Colour at end: Purple