food tests

Question 1

benedicts test

Answer 1

test for reducing sugars

Question 2

positive test for benedicts

Answer 2

colour range from green to red

Question 3

how to do test for non reducing sugars?

Answer 3

Do Benedict’s test and stays blue
4. Boil with acid then neutralise with alkali;
5. Heat with Benedict’s and becomes red

Question 4

iodine test

Answer 4

test for starch

Question 5

positive test for iodine

Answer 5

blue - black

Question 6

biruet test

Answer 6

test for proteins

Question 7

positive test for biruet

Answer 7

purple

Question 8

ethanol test

Answer 8

test for lipids

Question 9

how to carry out ethanol test?

Answer 9

Add ethanol then add water and shake

Question 10

positive test

Answer 10

white emulsion

Question 11

Describe a biochemical test to show that raffinose solution contains a
non-reducing sugar.

Answer 11

Heat with acid and neutralise;
2. Heat with Benedict’s (solution);
3. Red precipitate/colour

Question 12

Describe how you would test a piece of food for the presence of lipid.

Answer 12

Dissolve in alcohol, then add water and mix
2. White emulsion shows presence of lipid.

Question 13

A student carried out the Benedict’s test. Suggest a method, other than using a
colorimeter, that this student could use to measure the quantity of reducing sugar in a
solution.

Answer 13

Filter and dry (the precipitate);
2. Find mass/weight;