Inspired by At Home Science, we copied their Enzymes and Gelatin experiment last night. This experiment is best set up before a meal or snack, so that you can discuss the process of digestion while you eat as you are waiting for the gelatin to set.
Purpose: To explore how natural plant enzymes work to digest food.
- fresh pineapple (canned will not work as it’s been heat treated)
- package of gelatin – any color
- small cooking pot
- clear glass containers
- mixing spoon
Caution!!!: Adult supervision and assistance needed because a stove and a knife is used in this experiment.
Step 1. Remove the pineapple skin
Step 2: Take half of the pineapple and cube and place in a bowl. Set aside to eat as a snack.
Step 3: Take the other half of the pineapple and blend for a minute or two.
Step 4: Divide the amount in half again. Place half of the amount in a bowl.
Step 5. Place the other half in a small sauce-pot and cook for 5 minutes. It will boil, but that’s okay. Remove from heat.
Step 6. Prepare the gelatin according to the directions on the package (usually 1 cup of boiling water, stir 2 minutes until dissolved, then add 1 cup of cold water).
Step 7. Pour the gelatin into at least three bowls – one labeled none, one labeled hot (or heated), one labeled cold (or unheated). Into the bowl labeled none, just add gelatin. Into the bowl labeled hot, add the gelatin and one teaspoon of heated pineapple. Into the bowl marked cold, add the gelatin and one teaspoon of unheated pineapple.
Step 8. Record “before” observations if you desire. My oldest noticed that the heated pineapple sank bits sank, but the cold pineapple floated to the top. Also, note that before they are chilled, all of them are liquid.
Step 9. Place the glass bowls in the refrigerator for 4 hours.
Step 10. Now is a good time to eat a meal or a snack (like the pineapple you cubed in step 2, and discuss the process of digestion. Discuss how enzymes break down protein into smaller pieces, how enzymes are naturally present in some foods, like pineapple (bromelain) or papaya (papain). Discuss how eating fresh pineapple or papaya with your meals helps you to digest proteins and for that reason it is a very good addition to your diet.
Step 11. After the meal, pace around and ask a million times, “is it ready yet?” Whine for added drama.
Step 12. After 4 hours, pull out the gelatin and observe:
Step 12.5 . Discuss observations:
What happened to the gelatin with no added pineapple?
It solidifies just like it is supposed to. Together with water, it forms a semi-solid colloid gel. It contains partially hydrolized proteins from the collagen of animals. (If you like gelatin deserts and you don’t want to be turned off from it forever, or have a sensitive child, I do not recommend further research on how gelatin is made).
What happened to the gelatin with the heat-treated pineapple? It also solidified.
Because heating the pineapple destroyed the enzyme, therefore it couldn’t break down protein.
What happened to the gelatin with the untreated pineapple?
It wouldn’t solidify and stayed in the liquid state.
Why? Because gelatin contains protein, and the enzyme (bromelain) in the pineapple remained intact; it broke down or digested the protein in the gelatin. Therefore, it would not solidify and remained in the liquid state.
Extra credit question:
After this experiment, can you answer why is fresh pineapple “better” for you than canned pineapple?
Because canned pineapple has been heat-treated in the canning process, thereby destroying the enzyme. It’s still good enough to eat, just fresh is better for you because it contains active enzymes.
Here’s more information about the health benefits of bromelain:
From the University of Maryland Medical Center:
Bromelain is a mixture of protein-digesting (proteolytic) enzymes found in pineapples (Ananas comosus ). Pineapple has been used for centuries in Central and South America to treat indigestion and reduce inflammation. Bromelain, which is derived from the stem and juice of the pineapple, was first isolated from the pineapple plant in the late 1800s. It is approved by the German Commission E to treat swelling and inflammation following surgery, particularly sinus surgery.
Bromelain can be useful in treating a wide range of conditions, but it is particularly effective in reducing inflammation associated with infection and injuries.
Bromelain can digest proteins and may help relieve stomach upset or heartburn, particularly when used in conjunction with other enzymes such as amylase (which digests starch) and lipase (which digests fat). One animal study suggests that the antibacterial effects of bromelain may help to control diarrhea caused by bacteria. However, human studies are needed.
Arthritis and other Inflammatory Conditions
Studies show mixed results, but one study suggested that a combination of bromelain, rutosid, and trypsin was as effective as some commonly used nonsteroidal anti-inflammatory (NSAID) medications for reducing pain associated with osteoarthritis. NSAIDs include ibuprofen (Advil or Motrin), naproxen (Aleve), and diclofenac (Voltaren), among others. Similarly, preliminary studies suggest that bromelain may also help reduce pain associated with rheumatoid arthritis, but the results are not definitive.