L2 - Food Tests

objectives

Carbohydrates - following on from L1

• Contain carbon, hydrogen and oxygen
• Made up of sugar units
• Substrate for respiration – energy release

Testing for Carbohydrates

There are two tests for Carbohydrates - Benedicts Solution which tests for reducing Sugars and Iodine which tests for the complex carbohydrate - Starch.

Testing for Fats

Fats go cloudy white when they are mixed with ethanol and then water.

Testing for Proteins

In the Biuret test the blue solution turns purple.

In the Biuret test we add Biuret Solution A (which contains Potassium Hydroxide) and shake it

Then we add Biuret Solution B (Which contains Copper Sulphate)

If the mixture turns Purple then proteins are present.