Bromelain in fresh pineapple prevents jelly from setting by digesting the gelatine protein.

1. Open a can of pineapple pieces and set aside.
2. Cut fresh pineapple into pieces similar in size to the canned ones.
3. Place several pieces of fresh pineapple in one cup and canned pineapple in another. Label if needed.
4. Prepare jelly crystals with boiling water according to packet instructions.
5. Pour the jelly mixture into the cups with fruit, and also into plain cups with no fruit.
6. Refrigerate until set. Compare whether the jelly with fresh pineapple, canned pineapple, or no fruit has set properly.

Pineapple Enzymes and Gelatin - The Sci Guys:

📄 DIY Science – Enzymes in Action - National Science Week 2023: https://www.scienceweek.net.au/wp-content/uploads/2023/06/Enzymes-in-Action.pdf

• Try adding other fruits such as kiwi, papaya, or mango to the jelly to test if they affect setting.
• Cook fresh pineapple before adding it to jelly to see if the enzyme is destroyed by heat.

• Adult supervision required when cutting pineapple with a knife.
• Adult must handle boiling water when preparing jelly.
• Avoid touching eyes after handling pineapple.

• Why does fresh pineapple prevent jelly from setting, while canned pineapple does not? (Fresh pineapple contains bromelain, a protease enzyme that digests proteins like gelatine. Canning destroys the enzyme with heat, allowing the jelly to set.)
• Why does fresh pineapple prevent jelly from setting, while canned pineapple does not? (Fresh pineapple contains bromelain, a protease enzyme that digests proteins like gelatine. Canning destroys the enzyme with heat, allowing the jelly to set.)
• What other foods contain enzymes that affect proteins? (Kiwi, papaya, fig, and mango contain proteases that can prevent jelly from setting.)