Gelatin is a protein that comes from the connective tissue in the hoofs, bones, tendons, ligaments and cartilage of animals. Vegetable gelatin, agar, is made from seaweed. Gelatin dissolves in hot water and hardens with cold. We can put all kinds of fruit in it to make terrific desserts-but we’re told on the package not to add raw pineapple. Why?
Things Required:
1 envelope of unflavoured gelatin
1/2 cup of cold water
A few bits of raw pineapple (or frozen pineapple juice)
A can of pineapple chunks
1½ cups of boiling water
Directions:
Stir gelatin in the cold water and let it stand for one or two minutes. Then add the boiling water and stir until the entire gelatin is dissolved. Pour into 2 cups or dessert dishes. To one, add raw pineapple bits or frozen pineapple juice. To the other, add canned pineapple bits or canned juice. Put both in the refrigerator.
This Is What Happens:
The gelatin with the canned pineapple becomes firm. The gelatin with the raw pineapple remains watery.
Science Behind It:
Pineapples, like figs and papayas, contain an enzyme that breaks proteins down into small fragments. If you put raw pineapple in gelatin for a dessert or fruit salad, this enzyme digests the gelatin molecules and prevents the gel from becoming solid. It remains liquid.
Cooking stops the enzyme from working. That’s why you can add canned pineapple to the gelatin with no bad effects. Since it has been heated, it no longer contains the active enzyme.
