In 1961, a technique for tenderizing beef was patented. It involved injecting papain, an enzyme made from papaya, directly into the bloodstream of living animals.
The white powder sold as "Meat Tenderizer" is composed mainly of an enzyme extract from the papaya, called papain, usually with added salt, sugar and anticaking agents. The enzyme papain breaks down tough meat fibers. Papaya juice has been used for centuries in South America to tenderize meat.