Simple Vs Complex Sugar

Testing for simple sugars

Aim- To test a sample of food to determine whether it contains simple sugars.

Equipment- Bunsen burner, test tube tongs, Benedict's Solution, a sample of food

Method-

1. Place about 2 ml if the sample into a test tube an then add 5 drops of Benedict's Solution.
2. Heat with a Bunsen until it changes colour. Do not boil

Results- A positive test for a simple sugar result in the Benedict's Solution changing from a blue colour to a brown/orange colour.

Discussion- The solution changed from blue to brown because there were simple sugar's present in the apple sample.

Conclusion- The colour change from blue to brown justifies that there were simple sugar present in the apple

Testing for complex sugars

Aim- To test if a sample of food contains complex sugars.

Equipment- Test tube, food sample, iodine solution

Method-

1. Place about 2 ml of the sample in a test tube.
2. Add about 3-5 drops of iodine and mix.

Results- The colour of the solution turned from brown to black.

Discussion-If complex sugars (i.e. starch) are present the iodine solution will change form a brown colour to a black colour.

If the iodine solution does not change colour then no complex sugars are present.

Conclusion- There are traces of complex sugar present in the bread sample.