Difficulty of Project
Less than $20.00
Caution must be used when handling iodine.
Readily available or easily purchased from the grocery store
Approximate Time Required to Complete the Project
One to two hours to collect the data; one day to prepare the science fair display
- ¼ cup of 10 different foods such as rice, potato, apple, carrot, broccoli, pasta, nuts, milk, cereal, and ice cream (other foods may be substituted for these foods)
- 10 bowls
- 10 spoons
- 10 coffee filters
- Funnel (large enough to fit a coffee filter)
- 10 clear plastic cups
- Masking tape
- 10 drops of iodine
- medicine dropper
Grains, potatoes, corn, and beans are sources of starch. Fruits and vegetables also have starch. All starch is basically a glucose or sugar. Some starches such as breads and candies are typically high in calories and produce a quick energy high but are not able to sustain the energy level. Pasta, however, is different. Pasta breaks down in the body at a slower rate allowing the energy use to be prolonged. That is why athletes will eat a lot of pasta before an athletic event. Most starches are fairly inexpensive so they can be used to feed large amounts of people with less money.
In this investigation, several food items are tested to determine whether they contain starch.
starch: white, odorless, tasteless carbohydrate; can be converted to energy
carbohydrate: a type of compound that includes sugars and starches and serves as an energy source
glucose: a sugar in many fruits
Starch is a carbohydrate that makes energy in the body.
- What foods contain starch?
- How does starch help the body?
- Gather the necessary materials.
- Crush each of the 10 foods selected in a bowl. Add water and mix until each form a soupy mixture.
- Place a coffee filter in the funnel. Pour one of the soupy mixtures into funnel. Put the funnel over a clear plastic cup. Add water. Fill the cup a quarter of the way full. Using the masking tape, label the cup.
- Using the medicine dropper, put one drop of iodine into the plastic cup. Record the results. If the mixture turns dark blue, the food contains starch.
- Repeat Steps 3 – 4 for all the food samples.
“What You Need to Know About Complex Carbohydrates” by Laura Dolson at About.com
“Cereals, Foods Rich in Starch” at http://www.earthlypursuits.com/FoodSaveShare/FoodSaveShare5.htm
“Sweet, Sweet Carb” at http://www.chem4kids.com/files/bio_carbos.html
“Carbohydrates” at http://www.healthcentral.com/diabetes/diet-000042_3-145.html