Food tests

Question 1

What food test is used for starch?

Answer 1

Iodine test

Question 2

What is the method of iodine test?

Answer 2

1. Add 2 drops of iodine solution on the food smaple on a white tile or in a test tube

Question 3

What are the observations and conclusions from an iodine test?

Answer 3

1. Starch present = Blue-black obtained
2. Starch not present = Brown obtained

Question 4

What if the food test for reducing suagrs?

Answer 4

Benedict test

Question 5

what are reducing sugars?

Answer 5

Glucose, lactose, maltose, fructose

Question 6

What is requried for reducing sugars test?

Answer 6

Water bath

Question 7

what is the method for reducing sugars test?

Answer 7

1. Add 2cm3 of Benedict solution into 2cm3 of food test solution.
2. Shake the test tube
3. Leave the test tube in the beaker until boiling.
4. Observe the colour change of the solution.

Question 8

What are the observations and conculsions fron the Benedict test?

Answer 8

Brick-red ppt= High concentration of reducing sugars present
Remains blue= Reducing sugars absent

Question 9

what is the food test for fats?

Answer 9

Ethanol-emulsion test

Coconut oil seems to be a commonly tested foo item for fats

Question 10

What is the method for fat test?

Answer 10

1. Add 2.0 cm3 of Ethanol to food sample in test tube.
2. Shake the test tube vigriously.
3. Add 2.0 cm3 of water into the mixture
4. Shake the mixture

Question 11

what is the method for fats test (solids)?

Answer 11

1. Let the particles settle
2. Pour the solution slolwy into another test tube
3. Add 2.0cm3 of water to the mixture

Question 12

What are the observations and conclusions frome the Fats test?

Answer 12

White emulsion= Fats present
Clear = Fats absent

Question 13

What is the test for proteins?

Answer 13

Biuret test

Question 14

What is the method for Biuret test?

Answer 14

1. Add Biuret dropwise into the food solution.
2. Shake after every drop
3. Observe the colour change of the solution.

Question 15

What are the observations and conclusions of the Biuret test?

Answer 15

1. Violet = Proteins present
2. remains blue = Proteins absent

Question 16

What are the two things that I need to do if I have to use a solid sample for buriet and benedict test?

Answer 16

1. Cut/crush the solid food sample given.
2. Add distilled water, equal to the given volume of the food sample