Hands-on Science Carnival Activity Stations: Chemistry

Food Science: There's Iron in My Cereal!

[Shopping List: various types of cereal including high iron; magnet; sandwich bag; large clear bowls; magnifying glass; 2 oz solo cup and lids; popsicle sticks for stirring; water]

1. Use electrical tape to attach small magnet to the bottom of a 2 oz cup
2. Pour pre-ground cereal into the cup, or pour in some whole cereal and have the kid grind it up. It must be a powder, so using the pre-ground cereal is more likely to reach success.
3. Add water to make a soup.
4. Place a lid on the cup and shake for several minutes. Look for iron shavings that come out of the cereal and attach to the magnet at the bottom of the cup. You might have to dump the cereal out of the cup and rinse with water to see them.
5. Compare the amount of iron you can collect in a given amount of time from one cereal to another. Why might they be different?
6. Rinse and reuse the cups please! An alternate method is to place the cereal in a bowl with water, and stuff a small balloon with a magnet (don't blow up or tie the balloon!). Holding the end of the balloon, move it through the cereal for a minute or two. The iron shavings should be visible on the outside of the balloon. To get the magnet out of the balloon without letting the iron shavings attach to the balloon, turn it inside out.

What's Happening: Iron is a crucial component of a balanced diet, and some people might not consume enough iron naturally to sustain themselves. Because of this, many food manufacturers have started to add iron to some food to boost the average daily intake of iron. The added iron can take the form of ferrous sulfate (FeSO4) or elemental iron (Fe). The iron you see in this cereal is elemental iron. Acids in the digestive tract change this iron into a form easily absorbed and used by the body. The magnets attract the small iron filings that are present in the cereal, separating them from the other cereal components. Total includes 100% of the recommended daily iron intake, while shredded wheat contains a mere 8% - this is why you can see iron filings come out of the Total cereal.