Mainly from its stem, pineapple contains a proteolytic enzyme, bromelain, which breaks down protein. If having sufficient bromelain content, pineapple juice can thus be used as a marinade and tenderizer for meat. Pineapple enzymes can interfere with the preparation of some foods, such as jelly or other gelatin-based desserts, but would be destroyed during cooking and the canning process. The quantity of bromelain in the fruit is probably not significant, being mostly in the inedible stalk. Furthermore, an ingested enzyme like bromelain is unlikely to survive intact the proteolytic processes of digestion.
