Different foods have different nutrients

	Project title: Different foods have different nutrients
Difficulty level:	Middle school
Main link:	None

Hypothesis:

Different types of foods contain different mixes of fat, starch, protein and sugar.

Materials:

8 test tubes
test-tube rack
test-tube holder
marker
iodine
distilled water
newsprint
Benedict's solution
stirring rod
labels
Buret reagent

Foods used in the experiment:
-orange juice
-milk
-fish
-chicken
-egg white
-lettuce
-soy oil
-carrots

The Procedure:

Label 8 test tubes after the different types of foods that you are using in the experiment.

PART I: Testing for Carbohydrates (starch)

1. Use a dropper to place 10 drops of each food in the test tube with the matching label. Add 3-4 drops of iodine to each test tube.

2. Record which tubes have food that turn blue-black in color.

3. On a scale of 0 to 4, record the level of starch contained in each tube.

4. Empty the tubes and wash them.

PART II: Testing for Carbohydrates (sugar)

1. Use a dropper to place 10 drops of each food into a test tube with the matching label. Add 10 drops of Benedict's solution to each test tube.

2. Heat the test tubes for 2 to 3 minutes in a hot water bath.

3. Record which tubes have foods that change color. Those that do contain sugar. Blue = none, Blue-Green = small trace, Green = small quantity, Yellow = some, Orange-Red = a lot.

4. Empty the tubes and wash them.

PART III: Testing for protein

1. Use a dropper to place 10 drops of each food on a test tube with the matching label. Add 10 drops of Buret reagent to each test tube.

2. Look at the contents of each test tube. For better results, place the tubes against a white background.

3. On a scale of 0 to 4, record the level of proteins for each food. The food that turns the most pinkish-purple contains the most amount of protein.

4. Empty the tubes and wash them.

PART IV: Testing for Lipids

1. Use a dropper to place 1 drop of each food onto the newsprint.

2. Take note of the translucence of each food substance.

3. On a scale of 0 to 4, record the level of lipids for each food. The most translucent paper contains the most amount of lipid.

Results:

Food types Starch Sugar Proteins Lipids

orange juice 1 4 0 0
milk 0 2 3 2
fish 0 0 3 2
chicken 0 0 4 3
egg white 0 0 4 1
lettuce 3 2 0 0
soy oil 0 0 2 4
carrots 3 3 1 0

Pictures:

Food mix