Carbohydrates.
We can detect the presence of starch by adding a few drops of iodine. See what happens!
We can test for glucose and some other sugars by adding a few drops of  Benedict's solution to a test tube containing a solution of the food and heating it gently. See what happens!

Proteins.
Proteins react with Biuret solution and sodium hydroxide solution to make a delicate lilac colour.
Click here to remind yourself what happened in our experiment.

Food Tester's Challenge! 
Click here to complete the challenge!