Papain

More About The Value of Paw-Paw Latex

SOME notes by Mr. B. E. V. Parham, in the Fiji Agricultural Journal, give the latest information on the - subject of Papain (the latex of the paw paw), for which there hajs been some demand.

The “Agricultural Journal of Ceylon”, Vol. XCIII, No. 4, October, 1939, supplied the following information.

The latex containing the papain is best obtained from full-grown, or nearly full-grown, well-developed green fruit by making 2 to 4 longitudinal incisions not more than 1/8 inch deep. This opera tion may be repeated every three to seven days. It has been found that better yields are obtained if only a few incisions are made at a time, the tapping being done over a longer period until the fruit is covered with incisions approxi mately 1 cm. apart. The flow is most abundant in the early morning. Very young fruits give a latex that is rather weak in digestive power, while ripe fruits ‘ give verv little, if any, milky juice.

Only non-metallic containers, such as glass or porcelain dishes, should be used to collect the latex, because the juice acts orj the metal and becomes dis coloured. Coagulation soon begins and the mass adhering to the surface of the fruit must be carefully scraped off. Con siderable time and labour would be .saved if a convenient and efficient vessel could be devised which could be quickly put in place to receive the juice, per mitting the operator to proceed to the next tree in the meantime.

The juice must be dried promptly after it is collected, or decomposition, which destroys the value of the product, will occur. Sun-drying is practised to some extent, but it is much more satisfactory to dry the latex in a properlv ventilated . oven operated at 50 to 55 deg. Cent.

One form of drier is about three feet broad, three feet deep and six fqet long.

The sides and ends are made of brick, and openings are provided at both ends, one for the flue and the other to admit fuel. A foot from the top, which is open, a sheet of iron is placed, and upon this one or two inches of sand are laid to modify and distribute the heat arising from the fire beneath. The coagulated juice is spread upon brown linen stretched upon frames, which are made to fit the top of the drier. The tem perature should not exceed 50 to 55 deg Cent., since great heat destroys the fer ment. The dry and flaky material can be ground in a coffee-mill, preferably when the material is warm, and it should then be in the form of a light cream coloured powder. This powder should be placed in bottles, which should be tightly sealed.

Little information is available as to yields. Amounts of papain extracted per plant vary considerably: 20 to 250 grams per tree, or from 60 to 350 lb. of dried latex powder per morgen may be produced. Coagulated latex produces 25 per cent, of its weight of dried powder.

The latex is harvested through three seasons. By the fourth season the fruit is so high on the trunk that the cost of collecting the juice becomes prohibitive Mr. Parham says that advice from HM Government Agents in Australia states that this product was. until April 1948, realizing approximately 255. per pound fob Australian currency, but that since then the market price steadily de creased until June when it touched 14s 6d. per pound for first grade. There is now a slight improvement in price.