!! required practical 3

Question 1

how to test for the presence of sugar in food

which colour will it turn

Answer 1

add Benedict’s reagent and heat for about two minutes

turn yellow, red or green if there is any present

exact colour depends on concentration

Question 2

what is the first step of testing for either carbohydrates, lipids or proteins

Answer 2

to grind up the food and add distilled water to dissolve some of the food

Question 3

how to test for the presence of protein in food

which colour will it turn

Answer 3

add Biuret solution

will turn mauve or purple if protein is present

Question 4

how to test for the presence of starch in food

which colour will it turn

Answer 4

iodine solution

turn blue-black is starch is present