I love my grandmother’s carrot, pineapple and jelly pudding. It’s always a hit, so I decided to make one for Arthur Scott’s birthday party today. Unfortunately, I didn’t have tinned pineapple in the house like the recipe called for. The alternative was to put boiled pineapple in, but I was feeling a bit lazy. How could it really matter whether I boil the pineapple or not? So I took a chance and skipped the boiling. Big mistake. I forgot that raw pineapple has some pretty vicious protein guzzling enzymes. They ate my jelly.

This is what happened. Jelly is jelly because it contains gelatin. Gelatin is made from a protein called collagen, which is responsible for trapping water and making the jelly set. This is what normally happens - if you don’t add raw pineapple to the gelatin. Pineapple contains a really aggressive enzyme called bromelain, which breaks down proteins. The bromelain chews up the collagen so that it can’t trap the water. Now the collagen can’t make the jelly, well, jelly-ish anymore. The recipe calls for boiling the pineapple first because the heat inactivates the bromelain so that it can’t chow the gelatin. Now you know why the pineapple ate my jelly.

By the way, not all fruits have such vicious enzymes, but bromelain has some distant enzyme relatives in figs (ficin), kiwi fruits (actinidin) and papaya (papain). Bromelain and papain are the most commonly used enzymes in meat tenderizers - used to make your steak soft and tasty.

Want to dig deeper? See if you can find the answers to these questions:

1. Where do you find collagen in nature and what does it do?
2. What is an enzyme?
3. Gelatin isn’t the only protein that comes from animals. What is rennet and where does it come from? What is it used for?

Feeling creative?

Make the following recipe:
https://www.simplyrecipes.com/recipes...

Practical project:

https://teachbesideme.com/fruit-enzym...

Add our variation to the experiment: try boiled kiwi, pineapple or papaya versus their unboiled counterparts.