Look no further than your Thanksgiving feast for an opportunity to use chemistry to explore the world! These Thanksgiving dinner science projects use chemicals, foods, and some basic lab items. Perform tests on your Thanksgiving dinner to see which foods contain for macronutrients: starch, protein, and fat. You could also use our complete Chemistry of Food Experiment Kit to perform these and other experiments. Be sure to put on your personal protective equipment before you start experimenting.
What You Need:
- test tube rack
- test tubes
- pipets
- water
- solid or liquid food samples for testing
- wax pencil
- Spatula/scoop or teaspoon
- Lugol’s iodine
- Biuret reagent
- Sudan III stain
- Lab apron
- Goggles
- Gloves
Thanksgiving Dinner Science Project 1: Test Food for Starch
In this Thanksgiving feast science project, test for starch using Lugol’s iodine. First, you’ll make a solution using solid foods. If using liquid foods, this won’t be necessary. The solution will turn blue-black if starches are present.
What You Do:
1. To make your test solution, finely chop solid foods with a knife, or break them into small pieces and grind them up using the back of a fork. In a beaker or cup, measure 1/2 teaspoon of ground food to 2 teaspoons of water, and stir to make liquid solutions. For liquid foods (like milk), pour about 2 teaspoons of each into a cup or beaker. Label each solution with the wax pencil (which washes easily off glass) or a piece of masking tape and a permanent marker.
2. To a test tube, add 50 drops of solution to be tested. If using more than one food, mark its name on the test tube using a wax pencil. Make a chart and hypothesize about which foods contain starch.
3. Add 5 drops of Lugol’s iodine to each test tube and gently swirl to mix.
4. Note color change, if any. If it turns blue-black, the solution contains starch.
5. Record the results and compare the results to those of the following tests
What Happened:
Extra glucose is usually stored in a more complex carbohydrate called starch. When we eat foods with starch, our body breaks down the large starch molecules into simple sugars, like glucose, to use for energy. The energy from starch, along with other carbohydrates, allows us to think, move, and do everything else, from reading a book to running a race. Starch is part of a healthy diet, especially when it comes from whole-grain foods that also contain vitamins and minerals.
Thanksgiving Dinner Science Project 2: Test Food for Protein
In this Thanksgiving dinner science experiment, test food for protein using Biuret reagent. The blue solution changes to pink-purple when it reacts with protein.
What You Do:
1. Make a food solution, as indicated above.
2. To a test tube, add 50 drops of solution to be tested.
3. If testing more than one food, label each test tube.
4. Add 5 drops of Biuret reagent solution to each test tube. Swirl gently to mix.
5. Note color change, if any. Proteins will turn the solution pink or purple.
What Happened?
Protein strengthens your muscles and organs, helps your immune system, and controls many processes inside your cells. Your body also uses specialized protein molecules to make red blood cells, which carry oxygen to all parts of your body. Proteins are large, complex molecules made up of smaller “building blocks” called amino acids. Digestion breaks proteins into individual amino acids that come together to form new proteins that fit the needs of each individual cell. Protein is an essential part of our diet, but because it is complex, it’s difficult to digest, so we can only eat small amounts every day. Protein doesn’t get stored in the body, though, so it is important to eat it regularly.
Thanksgiving Dinner Science Project 3: Test Food for Fat
Use Sudan III to identify the presence of lipids (fats) in liquids in this Thanksgiving meal science experiment. Sudan III stains fat cells red.
What You Do:
1. Make a food solution as indicated above.
2. To a test tube, add equal parts of test solution and water until half full.
3. If testing more than one food, label each test tube.
4. Add 3 drops of Sudan III stain to each test tube. Swirl gently to mix.
5. A red-stained oil layer will separate out and float on the water surface if fat is present.
What Happened?
Fats and oils are both lipids. Lipids are molecules that are insoluble (won’t dissolve) in water. They transport vitamins, help form cell walls, and store energy long-term. Fats contain at least twice the amount of energy as carbohydrates and proteins. They do not, however, provide instant energy like starch and glucose do, but are used as storage. Eating too much food with fat or oil can be unhealthy, causing heart problems, since lipids flow through the bloodstream and can block your arteries. A healthy diet should include a few lipids, balanced by eating small amounts of protein every day.
