AY Honors/Palm Trees/Answer Key
- For the mining disaster, see Sago Mine disaster.
Sago is a powdery starch made from the processed pith found inside the trunks of the Sago Palm Metroxylon sagu. Sago forms a major staple food for the lowland peoples of New Guinea and the Moluccas.
Processed starch known as sago is also made from some cycad plants, and is a less frequent food source for some peoples of the Pacific and Indian Oceans. There is a large difference both biologically and dietarily between the two types of sago. Sago as a major dietary food source comes mainly from a palm in the genus Metroxylon. Despite their common name, cycads are not palms (i.e. they are not members of the family Arecaceae but rather from Cycadaceae, a vastly different taxonomic order: cycads are gymnosperms, while palms are angiosperms).
Because sago flour made from Metroxylon is the most widely used form, this article discusses sago from Metroxylon unless otherwise specified.
Preparation
Sago (Metroxylon) is made through the following steps:
- Felling the sago palm tree;
- Splitting the trunk open lengthwise;
- Removing the pith;
- Crushing and kneading the pith to release the starch;
- Washing and straining to extract the starch from the fiberous residue;
- Collection of the raw starch suspension in a settling container.
The sago starch is then either baked (resulting in a product analogous to bread or a pancake) or mixed with boiling water to form a kind of paste. Sago can be made into steamed puddings such as sago plum pudding, ground into a powder and used as a thickener for other dishes, or used as a dense glutinous flour.
In Malaysia and Indonesia, sago from Metroxylon is used as a starch in making noodles, white bread, and sago pearls (similar to tapioca). In India pearl sago (a form of sago) is called Sabudana, and is used in a variety of dishes including khichdi, wafers and puddings. The source of this sago is most likely Metroxylon rather than the cycad version.
Sago from the cycad is very different, because unlike Metroxylon, cycad seeds contain highly poisonous compounds. Consumption of cycad seeds has been implicated in the outbreak of Parkinson's Disease-like neurological disorder in various locations in the Pacific such as Guam. Highly toxic cycasin and BMAA compounds are found in most parts of the plant. These must be removed through extended processing before any part can be safely eaten. First, the pith made from the trunk, root, seeds is first ground to a coarse flour, washed carefully to leach out natural toxins, then dried and cooked to become a starchy granular fecula similar to tapioca and is used for many of the same purposes.
Nutrition
Sago flour (Metroxylon) is nearly pure carbohydrate and has very little protein, vitamins, or minerals. However, as sago palms are typically found in areas unsuited for agriculture, sago cultivation is often the most ecologically appropriate form of land-use, and the nutritional deficiencies of the food can often be compensated for with other readily available dietary items.
One hundred grams of dry sago yields 355 calories, including an average of 94 grams of carbohydrate, 0.2 grams of protein, 0.5 grams of dietary fiber, 10mg of calcium, 1.2mg of iron, and negligible amounts of fat, carotene, thiamine, and ascorbic acid.
Sago can be stored for weeks or months, although generally it is eaten quickly after it is processed.
Other Uses
In addition to its use as a food source, the leaves and spathe of the sago palm are used for construction materials.
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References
- Flach, M. and F. Rumawas, eds. (1996). Plant Resources of South-East Asia (PROSEA) No. 9: Plants Yielding Non-Seed Carbohydrates. Leiden: Blackhuys.
- Lie, Goan-Hong. (1980). "The Comparative Nutritional Roles of Sago and Cassava in Indonesia." In: Stanton, W.R. and M. Flach, eds., Sago: The Equatorial Swamp as a Natural Resource. The Hague, Boston, London: Martinus Nijhoff.
- McClatchey, W., H.I. Manner, and C.R. Elevitch. (2005). Metroxylon amicarum, M. paulcoxii, M. sagu, M. salomonense, M. vitiense, and M. warburgii (sago palm), ver. 1.1. In: Elevitch, C.R. (ed.) Species Profiles for Pacific Island Agroforestry. Permanent Agriculture Resources (PAR), Holualoa, Hawaii.
- Pickell, D. (2002). Between the Tides: A Fascinating Journey Among the Kamoro of New Guinea. Singapore: Periplus Press.
- Rauwerdink, Jan B. (1986). "An Essay on Metroxylon, the Sago Palm." Principes 30(4): 165-180.
- Stanton, W.R. and M. Flach, eds., Sago: The Equatorial Swamp as a Natural Resource. The Hague, Boston, London: Martinus Nijhoff.
