Food tests

Question 1

test for lipids and result if present

Answer 1

1. add ethanol
2. shake
3. add water
4. milky white emulsion forms

Question 2

test and positive result for non-reducing sugars

Answer 2

1. add benedict’s solution
2. heat
3. no colour change; stays blue
4. add HCL and boil
5. neutralise with sodium hydroxide
6. add benedict’s solution
7. heat
8. positive result shows colour change of blue to red

Question 3

test and positive result for reducing sugars

Answer 3

1. add benedict’s solution
2. heat
3. colour change from blue to red

Question 4

test and positive result for proteins (enzymes, ect.)

Answer 4

1. add biruet reagent; potassium hydroxide and copper sulphate
2. colour change from blue to lilac