Organisation: Chapter 2

• What does the Benedict Test for?

  Tests for reducing sugars. Put the 5cm^3 of that sample into a test tube. Prepare a water bath at 75 degrees Celsius. After the water bath is heated, add 10 drops of Benedict solution to the test tube. Place it in the water bath for 5 minutes.
• What are the results of the Benedict Test ?

  If the solution has no reducing sugars the solution will stay blue, and if the sugars are present the solution should turn green, yellow or brick red depending on the concentration.
• What does the Iodine Solution Test For ?

  Tests for starch. Take 5cm^3 of the food sample and add a few drops of iodine solution. This turns the solution a brown - orange colour. Gently shake the test tube and if the sample did contain starch the solution should change to a blue - black solution.
• What does the Biuret Solution Test for ?

  Tests for proteins. Add 2cm^3 of the food sample to the test tube and another 2cm^3 of biuret solution to the sample turning it blue. Gently shake the test tube and if the solution contained proteins the solution should turn pink - purple.
• What does the Sudan III Test for ?

  Tests for Lipids. Add 5cm^3 of the unfiltered food sample to the test tube and add 3 drops of the Sudan III stain solution to the test tube and gently shake it.
• What happens if the solution contains Sudan III solution.

  If the lipids are present and didn't get stained by the Sudan III solution, as the lipids separate from the water as its not soluble a bright red layer should form at the top.