Overview

Most of the food items consumed by us come from living beings and contain carbon compounds such as protein, carbohydrates and lipids. The presence of carbohydrates (starch) in a food sample can be detected using Lugol’s solution as indicator whereas the presence of proteins in a food sample can be detected using Biuret solution as indicator. On the other hand, the presence of lipids in a food sample can be detected using Sudan red solution as indicator.

Learning objectives

After completing this module, you will be able to:
 - Explain the process of Lugol’s test for carbohydrates.
 - Describe the process of Biuret test for proteins.
 - Explain the process of Sudan red test for lipids.
 - Test food samples for the presence of carbohydrates, proteins and lipids.