Papain 149
through a 10 mesh sieve. The whole powder is packed in polythene bags, followed by
keeping in sealed air tight and light-proof containers (clay pots or metal cans), and
finally, kept in a cool and dry place. Metal containers should be lined with polythene.
This is not possible at small scale. Crude papain has less value unless it is prepared in
the desired grade of demand which is measured by the activity of enzyme. The crude
papain, thus prepared, is exported to Europe and United States where it is further
refined and sold as powder or in the tablet form under various trade names.
13.9 MEDICINAL, INDUSTRIAL AND PHARMACEUTICAL USES
Papaya can be used as a diuretic (the roots and leaves), anthelmintic (leaves and
seed) and to treat bilious conditions (fruit). Parts of the plant are also used to combat
dyspepsia and other digestive disorders and a liquid portion has been used to reduce
enlarged tonsils. In addition, the juice is used for warts, cancers, tumours, corns and
skin defects while the root is said to help tumours of the uterus. Root infusion is also
used for syphilis, and the leaf is smoked to relieve asthma attacks. The papaya eating
prevents rheumatism and the latex is used for psoriasis, ringworm and the removal
of cancerous growth (Nwofia et al. 2012). Papain has been employed to treat ulcers,
dissolve membranes in diphtheria, and to reduce swelling, fever and adhesions after
surgery. With considerable risk, it has been applied on meat impacted in the gullet.
Chemo-papain is, sometimes, injected in the cases of slipped spinal discs or pinched
nerves. Precautions should be taken because some individuals are allergic to papain
in any form and even to meat tenderised with papain. It is used in meat tenderisers;
the major meat proteins responsible for tenderness are the myofibrillar proteins and
the connective tissue proteins. Protease enzymes are used to modify these proteins
and papain has been extensively used as a common ingredient in the brewery and in
the meat and meat processing (Khanna and Panda 2007). Its importance as tenderis-
ers in the food industry is similar to collagenases, which have application in the fur
and hide tanning to ensure uniform dying of leather. It has for quite a long time been
used in pharmaceutical preparations of diverse food manufacturing applications
as the production of high quality kunafa and other popular local sweets and pas-
tries. Papain has been reported to improve meltability and stretchability of Nabulsi
cheese with outstanding fibrous structure enhancing superiority in the application
in kunafa, pizza and pastries (Abu-Alruz et al. 2009). Also as pharmaceutical prod-
ucts in gel-based proteolytic cysteine enzyme, papain presents antifungal, antibacte-
rial and anti-inflammatory properties (Chukwuemeka and Anthoni 2010). Papain
acts as a debris-removing agent, with no harmful effect on sound tissues because of
the enzyme’s specificity, acting only on the tissues, which lack the Al-antitripsine
plasmatic antiprotease that inhibits proteolysis in healthy tissues (Flindt 1979). The
mechanism of biochemical removal of caries involves cleavage of polypeptide chains
and/or hydrolysis of collagen cross linkages. These cross-linkages give stability
to the collagen fibrils, which become weaker and thus more prone to be removed
when exposed to the papain gel (Beeley et al. 2000). Papain-based gel has also been
reported as potential by useful in biochemical excavation procedures for dentin (Piva
et al. 2008). Carpaine, an alkaloid found in papaya leaves, has also been used for
medicinal purpose (Sankat and Maharaj 2001). Papain has advantages for being used