Food Tests

Question 1

Test for fat

Answer 1

1) Dissolve in ethanol (clear)
2) dribble in water (clear)
3) Cloudy = present (cloudy)

Question 2

Test for protein

Answer 2

1) mush in water
2) dilute with Biurets solution [copper sulphate + dilute sodium hydroxide] (blue)
3) turns purple = present (purple)

Question 3

Test for sugar

Answer 3

1) dissolve sample in water (clear)
2) add Benedict’s solution [copper sulphate (only!)] and boil/heat (blue)
3) changes to orange/brick red = present (red/orange)

Question 4

Test for starch

Answer 4

1) dissolve sample in iodine (orange/brown)
2) turns blue-black = present (blue-black)