Bromelains

Bromelain is an enzyme extract derived from the stems of pineapples, although it exists in all parts of the fresh plant and fruit. The extract has a history of folk medicine use. As a culinary ingredient, it may be used as a meat tenderizer. Bromelain is an enzyme extract derived from the stems of pineapples, although it exists in all parts of the fresh plant and fruit. The extract has a history of folk medicine use. As a culinary ingredient, it may be used as a meat tenderizer. The term 'bromelain' may refer to either of two protease enzymes extracted from the plants of the family Bromeliaceae, or it may refer to a combination of those enzymes along with other compounds produced in an extract. Although tested in a variety of folk medicine and research models for its possible efficacy against diseases, the only approved clinical application for bromelain was issued in 2012 by the European Medicines Agency for a topical medication called NexoBrid used to remove dead tissue in severe skin burns. Bromelain extract is a mixture of protein-digesting (proteolytic) enzymes and several other substances in smaller quantities. The proteolytic enzymes are sulfhydryl proteases; a free sulfhydryl group of a cysteine amino acid side chain is required for function. The two main enzymes are: Pineapples have a long tradition as a medicinal plant among the natives of South and Central America. The first isolation of bromelain was recorded by the Venezuelan chemist Vicente Marcano in 1891 by fermenting the fruit of pineapple. In 1892, Russell Henry Chittenden, assisted by Elliott P. Joslin and Frank Sherman Meara, investigated the matter more completely, and called it 'bromelin'. Later, the term 'bromelain' was introduced and originally applied to any protease from any member of the plant family Bromeliaceae. Bromelain is present in all parts of the pineapple plant (genus Ananas), but the stem is the most common commercial source, presumably because usable quantities are readily extractable after the fruit has been harvested. Produced mainly in parts of the world where pineapples are grown, such as Thailand or Malaysia, bromelain is extracted from the peel, stem, leaves or waste of the pineapple plant after processing the fruit for juice or other purposes. The starting material is blended and pressed through a filter to obtain a supernatant liquid containing the soluble bromelain enzyme. Further processing includes purification and concentration of the enzyme. After an hour at 50 °C (122 °F), 83% of the enzyme remains active, while at 40 °C (104 °F), practically 100% remains active. 8 minutes at 80 °C (176 °F) is sufficient to almost completely inactivate the enzyme. The proteolytic activity of concentrated bromelain solutions remains relatively stable for at least 1 week at room temperature, with minimal inactivation by multiple freeze-thaw cycles or exposure to the digestive enzyme trypsin. Along with papain, bromelain is one of the most popular proteases to use for meat tenderizing. Bromelain is sold in a powdered form, which is combined with a marinade, or directly sprinkled on the uncooked meat.