Food tests

Question 1

What is used to test for starch

Answer 1

Iodine solution

Question 2

What colour is the positive result for starch test

Answer 2

blue/black

Question 3

What colour is the negative result for starch test

Answer 3

iodine will stay orange

Question 4

How to carry out test for starch

Answer 4

• Add food sample to test tube (e.g. 5cm^3)
• Add a few drops of iodine solution
• Give the test tube a gentle shake and look for colour change

Question 5

What is used to test for sugars like glucose

Answer 5

Benedict’s solution

Question 6

What is the positive result for sugar test

Answer 6

Green - small amount
Yellow - moderate amount
Brick Red- lots

Question 7

What is the negative result for sugars

Answer 7

Solution will remain blue

Question 8

How to carry out the test for sugars like glucose

Answer 8

• Set up water bath to 80 degrees
• Add food sample to test tube (e.g. 5cm^3)
• Add some drops of benedict’s solution to test tube
• Place test tube in water bath for 5 minutes
• Note the colour change

Question 9

What is used to test for proteins

Answer 9

Biuret solution

Question 10

What is the positive result for the protein test

Answer 10

Lilac / purple

Question 11

What is the negative result for protein test

Answer 11

Solution will remain blue

Question 12

How to carry out the test for proteins

Answer 12

• Add food sample to test tube (2cm^3)
• Add biuret solution (dilute copper sulfate and sodium hydroxide)
• Gently shake it