Nope, sorry. Doesn't work. Freezing is actually a common way to keep enzymes and other proteins good and active. My husband (actually some of his students) did an experiment where they froze pineapple in liquid nitrogen, and then brought it back up to room temperature. It still kept gelatin from setting because the enzyme was still able to chew up the protein. MelissaH ← Melissa's right, freezing doesn't work. The students used liquid nitrogen (–320 deg F) and the enzyme still works. They also tried various forms of heat, all of which worked depending on the amount of heat applied. One group soaked the pineapple in car battery acid, which turned the pineapple black and stopped the enzyme from working, but I wouldn't suggest eating it. Another group used bleach, which deactivated the enzyme and turn the pineapple completely white. I suppose that you could wash it very well with water afterwards and it might be safe to eat. On a related note, Heston Blumenthal suggests that adding chili peppers deactivates the enzymes in pineapple, but I'm skeptical. I currently have an undergraduate student performing experiments to check this out.