Food Tests Required Practical

Question 1

What is the benedict test testing for?

Answer 1

Used to test for reducing sugars (glucose)

Question 2

How do you carry out the Benedict test?

Answer 2

1. Prepare iPhone sample and transfer 5 cm³ to a test tube
2. Prepare a water bath so that it’s set to 75°C
3. Add some benedicts solution to the test tube (about 10 drops)
4. Placed the test tube in the water bath using a test tube holder. Leave it there for five minutes
5. If the food sample contains a reducing sugar, the solution in the test tube will change from the normal blue colour to green, yellow or brick red. The colour change depends on how much sugar is in the food.

Question 3

What does the iodine solution test for?

Answer 3

Starch

Question 4

How would you carry out the iodine solution test?

Answer 4

1. Make a food sample and transfer 5 cm cubed to a test tube
2. Add a few wdrops of iodine solution. Gently shake the tube to mix the contents
3. If the sample contains starch, the colour of the solution will change from brownie orange to black or blue black

Question 5

What does the buiret test test for?

Answer 5

Proteins

Question 6

How would you carry out the buiret test?

Answer 6

1. Prepare a food sample and transfer 2 cm³ to a test tube.
2. Add 2 cm³ of buiret solution to the sample. Mix the contents of the tube by gently shaking it
3. If the food sample contains protein, the solution will change from blue to pink or purple

Question 7

What does the Sudan test for?

Answer 7

Lipids

Question 8

How would you carry out the Sudan three test?

Answer 8

1. Prepare a food sample but do not filter it
2. Add three drops of Sudan three stain solution to the test tube. Gently shake the tube
3. If the sample contains lipids, the mixture will separate out into two layers. The top layer will be bright red