Food Testing

Question 1

Testing for sugars

Answer 1

Place a food sample into a test tube
Prepare a water bath and set the temperature to 75 degrees
Add some benedict solution using a pipette (10 drops)
Place the tube in the bath for 5 minutes
If the sugar is present the tube will turn from blue to green,yellow or brick red .

Question 2

Testing for starch

Answer 2

Transfer a food sample to a test tube
Add iodine solution and gently shake the tube
If it is present the solution will turn from browny orange to black or blue

Question 3

Testing for proteins

Answer 3

Prepare a food sample and transfer it into a test tube
Add biuret solution and gently mix the contents
If protein is present the substance will turn from blue to pink or purple

Question 4

Testing for lipids

Answer 4

Transfer a food sample into a test tube
Use a pipette and add 3 drops of Sudan 3 solution into a test tube
If the lipids are present the top layer will be bright red