Why Not Papain

From Pacific Paw-Paws?

THE production of papain from the übiquitous paw-paw might be a profitable side-line for Pacific planters—particularly those in the South west Pacific who now must rehabilitate themselves, , .

Little if anything is known about this product in the South Pacific, but papain —a compound enzyme which even in minute quantities has the power to bring about great and rapid changes in other materials—has been in great demand in America for vears as a meat “tenderiser,” for clearing fruit juices and fermenting liquors, for preventing shrinkage and im proving the “handle” of wool and artifi cial wool, and as a digestive remedy.

Ceylon and Tanganyika have been the chief papain-producing countries with the Jaoanese Mandated Carolines, up until the outbreak of war, a close second.

America is the best market.

Although paw-paws are grown in Queensland and northern New South Wales no papain production is carried on in Australia.

The cost of the imported article is practically prohibitive, however, and the establishment of the industry in the Commonwealth was urged about 1943 and the Division of Industrial Chemistry, Council for Scientific and Industrial Re search (headquarters, Canberra), published a short paper on the subject.

It was stated at that time that the only factor likely to limit papain produc tion in Australia was. primarily,, labour; and secondly, cheap labour—if the pro duct was to compete against that pro duced by native labour in Tanganyika, Ceylon and the Carolines, etc.

Nothing further has been done about papain manufacture in the Common wealth, and the field is still open to planters in the Pacific who should have a ready-made market in Australasia, if not further afield.

Travellers in the tropics had remarked for generations that natives tenderised their meat by wrapping it in paw-paw leaves fa practice indulged in by many Europeans as well), but the protein digesting action of the juice was not recognised until late in the 19th century.

It was described by Roy in 1874, and studied by Wurtz (1878-80), Who partially purified the active component in the juice and called it “papaine.”

To-day’s papain is made from drying the juice (latex) of the green fruit, and grinding it into a powder.

Planters who are searching for a side crop to tide them over the first years of rehabilitation would do well to con sider paw-paws for papain. The tree grows wild in all Pacific islands and. apart from these bush trees, cultivated paw-paws reach maturity within 15 months.

Extensive inquiries about papain were made by Mr. and Mrs. A. E. Cridland before they returned to their plantation in Papua, in April.

In the 1945 report of the Imperial in stitute, London (one of whose aims is to further the utilisation of the raw material of British Colonies) mention is made of the “salt paste” method of papain preparation. In this process com mon salt is added to the moist latex, which is then allowed to dry to a thick paste.

It is claimed that this method avoids the serious loss of activity that com monly occurs with the usual methods of preparation. One of the disadvantages of the powder form of papain is that it

rapidly loses activity if stored for any length of time. This loss is due in part to the action of the oxygen in the air.