Sago. Metroxylon rumphii, Metroxylon laeve.
Sago. Sagou, Fr. Sago, G., It. Sagu, Sp.— Under this name the U. S. P. formerly recognized the starch obtained from the sago palms. Numerous trees, inhabiting the islands and coasts of the Indian Ocean, contain a farinaceous pith from which is extracted the starch in enormous quantities. In India and the East Indies it is obtained from several palms, viz.: Metroxylon Rumphii Mart. and M. laeve Mart."
The fruit of the Cycas circinalis, according to J. van Donjen, contains a poisonous glucoside, pakoeine. (P. J., May, 1903.)
According to H. von Rosenberg (Proc. A. Ph. A., xxvii, 140), pith cells of these palms consist mostly of starch when the large leaves have fallen off and the flowers are just taking their place. At this time the tree is felled, and the trunk cut into billets six or seven feet long, which are split in order to facilitate the extraction of the pith. This is obtained in the state of a coarse powder, which is mixed with water in a trough having a sieve at the end. The water, loaded with farina, passes through the sieve, and is received in convenient vessels, where it is allowed to stand till the insoluble matter has subsided. It is then strained off, and the farina which is left may be dried into a kind of meal or molded into whatever shape may be desired. For the consumption of the natives it is usually formed into cakes of various sizes, which are dried, and extensively sold in the islands. The commercial "Pearl" sago is prepared by forming the meal into a paste with water, and rubbing it into grains. It is produced in the greatest abundance in the Moluccas, but of the finest quality on the eastern coast of Sumatra. The Chinese of Malacca refine it so as to give the grains a fine pearly luster. Malcolm states that it is also refined in large quantities at Singapore.
Pearl sago is that which is now generally used. It is in small grains, about the size of a pin head, hard, whitish, of a light brown color, in some instances translucent, inodorous, and with little taste. It may be rendered perfectly white by a solution of chlorinated lime. Common sago is in larger and browner grains, of more unequal size, of a duller aspect, and frequently mixed with more or less of a dirty looking powder.
An average palm about fifteen years old will yield from 300 to 400 kg. of sago starch.
Sago meal is imported into England from the East Indies. It ia in the form of a fine amylaceous powder, of a whitish color, with a yellowish or reddish tint, and of somewhat musty odor.
Sago starch grains are oval or ovate and often truncated. As the article of commerce is partially cooked the grains are more or less altered. The individual grains usually show a large central area around which are the narrow, distinct altered lamellae which are sometimes traversed by radiating fissures. The starch grains vary from 0.015 to 0.080 mm. in length. When examined by polarized light the grains show a distinct cross. At one time sago flour showed considerable amounts of stone cells, hairs and calcium oxalate crystals, but as the product is more highly refined in recent years, these impurities have been eliminated.
Common sago is insoluble in cold water, but by long boiling unites with that liquid, becoming at first soft and transparent, and ultimately forming a gelatinous solution. Pearl sago is partially dissolved by cold water, probably owing to the heat used in its preparation. Chemically considered, it is a very pure natural starch, as the nitrogenous matter rarely amounts to more than one per cent., and the ash to one-half per cent., the remainder being starch and moisture.
Potato starch is sometimes prepared so as to resemble bleached pearl sago, for which it is sold. But, when examined under the microscope, it exhibits larger granules, which are also more regularly oval or ovate, smoother, less broken, and more distinctly marked with lamellae than are those of sago, and the hilum often cracks with two slightly diverging slits. Imitation sago is now made in the United States from various kinds of starch.
Sago is used exclusively as an easily digestible, non-irritating food. It is given in the liquid state, and in its preparation care should be taken to boil it long in water, and stir it diligently, in order that the grains may be thoroughly dissolved. Should any portion remain undissolved, it should be separated by straining. A tablespoonful to the pint of water is usually sufficient.