Testing Food for Biological Macromolecules/ Nutrients

In class 9/11/13, we did a lab to test food for biological macromolecules / nutrients. In the part 1 we had to observe the reactions of starch, protein, lipids, and sugars with benedict’s test, iodine test, Biuret test, and Sudan III test. For the benedict’s test we had to put each test tube in hot water in order to see a reaction. We found that sugars react to Benedict’s solution which is blue and changes to orange. Starches interact with Iodine which is brown and changes to a dark blue. Proteins react with Biuret which is lavender and changes to blue. Lipids react with Sudan III which is red and changes to bright red.

 

 

In part two, we tested 10 unknown food substances with each test, to identify the type of food, depending on the reactions to the Bendict’s, Sudan III, Biuret, and Iodine tests. We found that in the Benedict’s test six solutions reacted with food substances in tubes A, B, E, G, H, and J which indicates that these food substances contain sugars.

 

We found that in the iodine test it reacted to the food substances in tubes C, D, E, F, and G, which indicates that these substances contain starch. In the Biuret test it reacted to substances in tubes B, C, D, and E, which indicates that these food substances contain proteins.  In the Sudan III test it reacted to food substances in tubes A, F, I, and J, which indicates that these substances contain lipids.

 

 

                By testing food substances with Benedict’s, iodine, Biuret, and Sudan III tests, there reaction will indicate if they contain proteins, starch, sugars, and lipids.