Sago is a starch extracted from the pith of sago palm stems, Metroxylon sagu. It is a major staple food for the lowland peoples of New Guinea and the Moluccas, where it is called saksakand sagu. It is traditionally cooked and eaten in various forms, such as rolled into balls, mixed with boiling water to form a paste, or as a pancake.
Sago looks like many other starches, and both sago and tapioca are produced commercially in the form of “pearls”. Sago pearls are similar in appearance to tapioca pearls, and the two may be used interchangeably in some dishes. This similarity causes some confusion in the names of dishes made with the pearls. Because sago flour made from Metroxylon is the most widely used form, this article discusses sago from Metroxylon unless otherwise specified.
Metroxylon sago is made through the following process:
The sago palm is felled.
The trunk is split lengthwise and the pith is removed.
The pith is crushed and kneaded to release the starch.
The pith is washed and strained to extract the starch from the fibrous residue.
The raw starch suspension is collected in a settling container.
Palms are felled just before flowering, when the stems are richest in starch. One palm yields 150 to 300 kg of starch.
Sago flour from Metroxylon is nearly pure carbohydrate and has very little protein, vitamins, or minerals. However, as sago palms are typically found in areas unsuited for other forms of 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 foods.
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, 10 mg of calcium, 1.2 mg of iron, and negligible amounts of fat, carotene, thiamine, and ascorbic acid.
Sago can be stored for weeks or months, although it is generally eaten soon after it is processed.
Sago starch is either baked (resulting in a product analogous to bread, pancake, or biscuit) or mixed with boiling water to form a 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 flour.
The starch is also used to treat fibre, making it easier to machine. This process is called sizing and helps to bind the fibre, give it a predictable slip for running on metal, standardise the level of hydration of the fibre, and give the textile more body. Most cloth and clothing has been sized; this leaves a residue which is removed in the first wash.
In Indoneia and Malaysia, sago is a main staple of many traditional communities in New Guinea, Borneo, Maluku, and Sumatra. In Brunei, it is used for making the popular local cuisine called the ambuyat. It is also used commercially in making noodles and white bread. Globally, its principal use is in the form of tapioca-like “pearls” such as those often found in drinks and smoothies.
Sago starch is not just limited to its uses for the food industry, but can also be used as a key material input in various industries such as paper, plywood, and textile industry. Sago starch is used to make adhesives, paper, ethanol, high fructose glucose syrup, maltodextrin, cyclodextrin and monosodium glutamate.
Sago starch can converted further through fermentation to be used for producing biodegradable plastic and ethanol (gasohol). Its residual biomass can similarly be used as a feedstock for the production of power and heat.
Because many traditional peoples rely on sago as their main food staple, and because those supplies of sago are not unlimited, in some areas commercial or industrial harvesting of wild stands of sago can conflict with the food needs of local communities.
Pearl sago, a commercial product, closely resembles pearl tapioca. Both typically are small (about 2 mm diameter) dry, opaque balls. Both may be white (if very pure) or colored naturally grey, brown or black, or artificially pink, yellow, green, etc. When soaked and cooked, both become much larger, translucent, soft and spongy. Both are widely used in Indian, Bangladeshi and Srilankan cuisine in a variety of dishes, and around the world, usually in puddings. In India, pearl sago is called javvarisi, sabudana (Hindi), and saggubeeyam (Telugu) among other regional and local names, and is used in a variety of dishes such as desserts boiled with sweetened milk on occasion of religious fasts. In the UK both sago and tapioca have long been used in milk puddings, and have become confused to the extent that “sago” as sold in supermarkets is now almost invariably made of tapioca starch. In Ayurvedic medicine, it is believed that sago porridge can be an effective and simple food to “cool and balance one’s body heat” when taking strong medicine or antibiotics.
The sago palm, Metroxylon sagu, is found in tropical lowland forest and freshwater swamps across Southeast Asia and New Guinea and is the primary source of sago flour. It tolerates a wide variety of soils and may reach 30 meters in height. The palm genus Metroxylon contains several species: two of these, M. salomonense and M. amicarum, are less-important sources of sago in Melanesia and Micronesia.
Sago palms grow very quickly, up to 1.5m of vertical stem growth per year. The stems are thick and either are self-supporting or have a moderate climbing habit. The leaves are pinnate, not palmate. The palms will only reproduce once before dying; they are harvested at the age of 7 to 15 years, just before flowering, when the stems are full of starch stored for use in reproduction.
In addition to its use as a food source, the leaves and spathe of the sago palm are used for construction materials and for thatching roofs. The fibre can be made into rope.
The sago cycad, Cycas revoluta, is a slow-growing wild or ornamental plant. Its common names, “Sago Palm” and “King Sago Palm”, are misnomers since it is actually a cycad. Cycads are gymnosperms from the family Cycadaceae; palms are angiosperms (flowering plants) from the Arecaceae. The two taxa are completely unrelated. Interestingly, cycads are also a type of living fossil, having survived since at least the early Permian period.
Processed starch known as sago is made from this and other cycads. It is a less-common food source for some peoples of the Pacific and Indian Oceans. There are large biological and dietary differences between the two types of sago. Unlike Metroxylon palms (discussed above), cycads are highly poisonous: most parts of the plant contain the neurotoxins cycasin and BMAA. Consumption of cycad seeds has been implicated in the outbreak of Parkinson’s Disease-like neurological disorder in Guam and other locations in the Pacific.
Before any part of the plant may safely be eaten, the toxins must be removed through extended processing. First, pith from the trunk, root, and seeds is ground to a coarse flour and washed carefully to leach out natural toxins. It is then dried and cooked, producing a starch similar to tapioca or palm sago. Cycad sago is used for many of the same purposes as palm sago. In Sri Lanka it is known as Sawu or Sau, which is used to prepare famous porridge, named Sawu Kanda.
Barley (Hordeum vulgare) is an annual cereal grain, which serves as a major animal feed crop, with smaller amounts used for malting and in health food. It is a member of the grass family Poaceae. In 2005, barley ranked fourth in quantity produced and in area of cultivation of cereal crops in the world (560,000 km²).The domesticated form (H. vulgare) is descended from wild barley (H. spontaneum). Both forms are diploid (2n=14 chromosomes). As wild barley is interfertile with domesticated barley, the two forms are often treated as one species, Hordeum vulgare, divided into subspecies spontaneum (wild) and subspecies vulgare (domesticated). The main difference between the two forms is the brittle rachis of the former, which enables seed dispersal in the wild.
Species: H. vulgare
Wild barley comes from Epi-Paleolithic sites in the Levant, beginning in the Natufian. The earliest domesticated barley occurs at Aceramic Neolithic sites in the Near East such as the (PPN B) layers of Tell Abu Hureyra in Syria. Barley was one of the first crops domesticated in the Near East, at the same time as einkorn and emmer wheat.
Barley was alongside emmer wheat, a staple cereal of ancient Egypt, where it was used to make bread and beer; together, these were a complete diet. The general name for barley is jt (hypothetically pronounced “eat”); šma (hypothetically pronounced “SHE-ma”) refers to Upper Egyptian barley and is a symbol of Upper Egypt. According to Deuteronomy 8:8, barley is one of the “Seven Species” of crops that characterize the fertility of the Promised Land of Canaan, and barley has a prominent role in the Israelite sacrifices described in the Pentateuch (see e.g. Numbers 5:15). A religious importance extended into the Middle Ages in Europe, and saw barley’s use in justice, via alphitomancy and the corsned.
In ancient Greece, the ritual significance of barley possibly dates back to the earliest stages of the Eleusinian Mysteries. The preparatory kykeon or mixed drink of the initiates, prepared from barley and herbs, was referred to in the Homeric hymn to Demeter, who was also called “Barley-mother”.
The practice was to dry the barley groats and roast them before preparing the porridge, according to Pliny the Elder’s Natural History (xviii.72). This produces malt that soon ferments and becomes slightly alcoholic.
Tibetan barley has been the only major staple food in Tibet for centuries. It is made into a flour product called tsampa.