Does kiwi contain a protein digesting enzyme?
Yes, kiwi does contain enzymes that digest protein. Cooking the kiwi denatures the protein enzyme so that it can not act. Canning pineapple is also a cooking process that denatures the enzymes. Enzymes are proteins. Think of cooking egg white. The heating process denatures the egg white protein so that it is no longer soluble. The same happens to the enzymes when heated.