Food tests

Question 1

What is the test for sugar?

Answer 1

Benedict’s test

Question 2

What does the benedict’s test test for? How do you carry it out?

Answer 2

Sugar

• Prepare food sample and put 5cm cubed in test tube
• Prepare water bath at 75 degrees C
• Add about 10 drops of benedict’s solution and out test tube in water bath for 5 minutes ensuring it’s pointing away from you
• If it contains sugar, the solution will turn from blue to green, yellow or brick red

Question 3

How do you test for starch?

Answer 3

• Prepare food sample and transfer 5cm cubed to test tube
• Add a few drops of iodine solution
• If starch is present it will turn from orangey brown to black or blue black

Question 4

How do you test for protein?

Answer 4

• 2cm cubed food sample in test tube
• Add 2cm cubed of biuret solution and shake it
• If protein is present the blue solution will change to pink/purple

Question 5

How do you test for lipids?

Answer 5

• 5cm cubed food sample in test tube
• Add 3 drops of Sudan 3 stain solution and gently shake
• If lipids are present a bright red layer will form at the top of the solution

Question 6

What solution do you add to test for sugars?

Answer 6

Benedict’s solution

Question 7

What solution do you add to test for starch?

Answer 7

iodine solution

Question 8

What solution do you add to test for protein

Answer 8

Biuret solution

Question 9

What solution do you add to test for lipids?

Answer 9

Sudan 3 stain solution