You will need:
- Packet of jelly
- Fresh fruits (apple, kiwi and pineapple)
- 4 small bowls
Eat some jelly while figuring out what makes
jelly behave the way it does.
INSTRUCTIONS
- Ask an adult to help you by preparing some jelly following the instructions given on the packet.
- Cut the above-mentioned fruits into small pieces. Do not mix the fruits.
- Place the cut pieces of fruits in separate bowls.
- Take the jelly mixture and once you have followed the instructions, pour it into the 4 different bowls and leave it to set.
- 3 of the 4 bowls will have cut pieces of apple, kiwi and pineapple while the fourth bowl will have only jelly in it.
- Place all four bowls into the fridge. Once the estimated time is up and the plain jelly has set, remove all the bowls and check what has happened.
RESULT
Jelly is a flexible solid made up of thin protein molecules which are long. These molecules begin to get entangled as the jelly begins to cool, trapping the water between the molecules. While all fruits have a certain amount of protease in them, fruits like pineapple and kiwi specifically have a very high level of protease. Pineapple has an enzyme known as bromelain and kiwi has an enzyme known as actinidin. Both these enzymes cut up the protein molecules in the same way that the protein enzymes in our intestines help digest the proteins. As a result, while the plain jelly and jelly with apple pieces would have set, the jelly with kiwi and pineapple in it would not have set, no matter how much you tried.
