Thursday, March 13, 2008

Breaking Molecular Bonds - Jello and Pineapple

Lesson: Breaking molecular bonds in protein using enzymes
What Happened: We disintegrated Jello using pineapples

(With help from Anthony)

The ingredients

Before we added the pineapple

The Jello started to melt after a minute

The Jello was half dissolved by now


The Jello is almost fully dissolved by now

It's fully dissolved now

Warning: Do not add pineapple

Why did it do that?

(From Chempedia)

Jell-O gelatin was first patented in 1845 by Peter Cooper of Cooper Union.

Gelatin is a processed version of the protein collagen, a simple protein that makes up one-third of all proteins in the human body. The main source of the collagen that is used in Jell-O comes from hooves, bones, connective tissue found on cows, horses and pigs. Along with collagen, Jell-O consists of water, food coloring, sugar, and artificial flavors. Collagen is found in all living animals. This protein is what gives body parts strength, flexibility, and protection. There are five major categories of collagen that range from the fibers in your eyes to the structure of placentas. To harvest the collagen needed for gelatin the Jell-O Corporation turns to natural sources found in cows, horses, and pigs. The animals' body part's which were previously mention are ground up to expose the proteins within. After they are ground up the bio matter is then treated with a strong acid or base, which breaks down the cellular structures of the collagen to release the proteins from connective tissue. After the proteins become separated from the tissues the bio-mass is then discarded. Then, the mixture created from the released proteins (collagen proteins, which are the basis of Jell-O) and the strong acid or base is then boiled.

(From General Chemistry Online)
Pineapple contains a plant enzyme called bromelain that breaks down proteins. Bromelain 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 bromelain 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 bromelain and can cause severe pain if eaten.

Other uses for bromelain:

(From Wikipedia)
Bromelain can be used in a vast array of medical conditions. It was first introduced in this area in 1957, and works by blocking some proinflammatory metabolites that accelerate and worsen the inflammatory process. It is an anti-inflammatory agent, and so can be used for sports injury, trauma, arthritis, and other kinds of swelling. Its main uses are treatment of athletic injuries, digestive problems, phlebitis, sinusitis, and aiding healing after surgery.


Ruskin said...

I love that this experiment is so simple and effective and that you have explained it in such a thorough way.

Anonymous said...

Last year my teacher had us do this experiment for Biology. Now I am doing it for a Science Fair. You explained it better than my teacher did. Now I actually understand why it happend rather than just nodding my head 'yes' when in actuallity i have no idea what is going on. :)

Anonymous said...

You really have explained this perfectly - I actually understood this experiment :-) Thanks for creating this blog!! I will be checking in often.

Anonymous said...

This project of yours really helped me out for the background information on jell-o. Thanks!!! =]

rkraut said...

This gives a nice explanation of the enzyme in the pineapple that breaks the jello bonds between collagen fragments. But can you tell us what covalent bonds are formed between the fragments of collagen in jello that makes it gel? And do you know whether they actually put Transglutaminase in the jello powder, and if so, how can the enzyme work when you're pouring boiling water on it...doesn't that denature the enzyme?

Kathy said...

What you see is what you get on this blog! For deeper explanations, start with the links that we provide, but you'll have to do your own research

Jacob Peacock said...

I enjoyed that experiment! It was new to me. I have posted a similar experiment using keratin (as well as gelatin) on my blog if your interested:

maxx said...

thank you for years i have wondered why pineapple was not to be used ...and your site explained it quickly and thoroughly with some added extra info. on bromilean .thank you ....i will put your site in my favorites for use in the future maxx

Anonymous said...

I also did this expirement to but i did it in a different way but your website helped me understand why it didnt work thanks i willl be using this website even more <3

Anonymous said...

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Anonymous said...

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Anonymous said...

I did this experiment with unflavoured gelatin and nothing happened.