Nutrition Experiments

Starch

Get some starch powder, bread, potato or banana. Prepare a 1% starch solution (1 g/100ml water) and combine with three drops of iodine. Add three drops of iodine to the bread, potato or banana. The bread, potato or banana change colour from yellow-red to blue-black, indicating that bread, potato and banana contain starch.

Fat

Get some sunflower oil, butter, milk (full-fat) and orange juice. Rub each of the foods into brown paper. Add a few drops of water to a piece of brown paper (control) and dry the papers on a radiator. The pieces of brown paper containing oil, butter and milk each develop a translucent spot, whilst the brown paper with the orange juice and water does not. This indicates that sunflower oil, butter and milk contain fat, whilst orange juice and water do not.

A Reducing Sugar
Get some Benedict's solution, a Bunsen/hotplate, glucose powder, orange juice and cranberry juice. Prepare a 1% glucose mixture (1 g/100ml water). Combine 1 ml of the glucose solution and 1 ml of each of orange juice, cranberry juice, and water (control) and place each of these solutions in a  test tube. Add 1 ml Benedict's solution to each test tube. Heat each test tube in a beaker of hot water. The tubes containing orange juice and cranberry juice change colour from blue to brick-red. This indicates that orange juice and cranberry juice contain a reducing sugar.

Protein
Get some sodium hydroxide solution, copper sulphate solution, egg white/albumin powder, and milk. Prepare a diluted mixture of each of the egg white and milk by taking 1 ml of each food and mixing with 1 ml water in a test tube. Place a few drops of sodium hydroxide in each test tube followed by a few drops of copper sulphate mixture. The tubes containing milk and egg white change colour from blue to violet. This indicates that milk and egg white contain protein.