Purified proteolytic substance derived from papaya Carica papaya. Meat tenderiser. Also used to reduce chillhaze in beer. Used in the prepn. of precooked cereals and prodn. of protein hydrolysates Papain, also known as papaya proteinase I, is a cysteine protease (EC enzyme present in papaya (Carica papaya) and mountain papaya (Vasconcellea cundinamarcensis). (Wikipedia)