Why can't you put pineapple chunks in Jello?

Pineapple contains a plant enzyme called bromelin that breaks down proteins. Bromelin is used in many meat tenderizers for this purpose (and that's why cooking ham with pineapple makes it tender).

JellO packages warn you not to put pineapple chunks into the gelatin. Jello is a protein mesh with trapped pockets of liquid; the bromelin cuts the protein chains and keeps the gelatin from jelling properly.

Why do pineapples produce an enzyme that tenderizes meat? It's a defense mechanism. The sap of the pineapple plant contains much higher concentrations of bromelin and can cause severe pain if eaten.

Dr. Ron Rusay has written a simple experiment to demonstrate protein degradation's role in kitchen chemistry.

Author: Fred Senese senese@antoine.frostburg.edu

Copyright © 1997-2001 by Fred Senese
Comments & questions to senese@antoine.frostburg.edu
Last Revised 02/23/18.URL: http://antoine.frostburg.edu/chem/senese/101-hidden/consumer/faq/pineapple-jello.shtml