Suitable For
Grade 3
Difficulty
2
Time Required
<1 Hour
Supervision
Required
What’s it about?
Heating or grilling food causes many of the chemicals in food to change. These bio-chemical changes can cause the food to become softer and easier to digest, or can result in more pleasant tastes! In this science experiment, learn how toasting bread can lead to chemical changes that make for a tastier breakfast:
Topics covered
Starch, Dextrin, Indicator, Iodine
What will I need?
- TOASTED SLICE OF WHITE BREAD
- BOWL OF WATER
- IODINE SOLUTION
- DISPOSABLE TRAY
Procedure (Method)
Unfortunately, this section is only available in the e-book version of the project.
How does it work?
Unfortunately, this section is only available in the e-book version of the project.
This science experiment works because when iodine, an ‘indicator’, comes into contact with starch, a deep purple-blue coloured substance is formed and is a positive test for starch. The untoasted areas of the bread samples all turn purple/blue, which indicates starch, but the toasted surface either did not change colour or turned slightly brown/red indicating the presence of ‘dextrin’.
A starch molecule is much larger than a sugar molecule, and when starch is heated or toasted as in this experiment, it breaks apart into smaller, mildly sweet tasting sugar molecules, called ‘dextrin’. The dextrin allows it to taste better and be more easily digested.
Like the sound of it?
Why not check out the full worksheet in one of our popular e-books?
This particular science project can be found in any of the following Experiland e-books:
Experiland e-books contain detailed steps, including illustrations, to complete the science projects from start to finish.
