You may have heard that you can't make jam from pineapple and papaya because they contain various enzymes that won’t allow the flesh to gel. First and foremost, yes, these fruits don’t jam well because of certain enzymes. Second, you definitely can make jam from both if you use a few tricks.
What are these enzymes and what exactly are they doing?
The Enzyme Bromelain
To begin, let’s talk about the enzyme called bromelain. Pineapples are packed with the stuff, though particularly in the stem and skin.
Bromelain is known for its ability to break down protein chains. This gives it a culinary use as a tenderizer to soften up tough cuts of meat. In fact, it’s such a great tenderizer that when using pineapple juice as a marinade, you only have to actually marinate for a short time. Marinate too long and the meat will literally fall apart.
This enzyme is also why pineapple won't form into jam and jelly when gelatin is used, as the enzyme breaks down the gelatin. However, you can add agar-agar to neutralize this reaction.
In fact, this enzyme is so strong that pineapple processors have to wear gloves and masks since the juice will eventually eat away at the hands and face. When cutting up lots of pineapples, it isn’t uncommon to come away with dry, flaky skin or even small sores.
There is some research to see if this enzyme can be used to treat osteoarthritis, but results so far are still pending or inconclusive.
The Enzyme Papain
So that leaves papaya. Papayas contain an enzyme called papain. This enzyme is rich in the fruit and the latex of the tree. However, the amount in the fruit lowers as it ripens; whereas young, green papayas are packed with papain.
Papain, like bromelain, is often used as a tenderizer. South American natives used to use the fruit and juice to work on tough cuts of meat. Even today, papain is a key ingredient in powdered meat tenderizers.
Papain is also used in toothpaste as a teeth whitener. It has also shown to interfere with urine-based drug tests for cannabinoids.
So what is the best way to use these fruits in cooking? First off, feel free to continue eating them in juices, salads, or straight. However, when marinating meat, mix the juice or pulp with garlic, cumin seeds, oil, diced chilies, lime, and cilantro, and use it for chicken or pork. Be sure not to marinate for more than 30 minutes. This mixture can be used on fish, but only marinate for 10 minutes.
Personally, we're a fan of this marinade for goat and sheep. Use it on the toughest cuts or use it directly in a braising liquid for a phenomenal meal.