Soybean extraction meal (pellets)
|Infobox on Soybean extraction meal (pellets)|
|Example of Soybean extraction meal (pellets)|
|Stowage factor (in m3/t)||1.50 - 1.52 m3/t (pellets)|
|Humidity / moisture||7.3 - 13%|
|Risk factors||See text|
Soybean extraction meal (pellets)
The soybean (US) or soya bean (UK) is a species of legume native to East Asia, widely grown for its edible bean which has numerous uses. The plant is classed as an oilseed rather than a pulse by the UN Food and Agricultural Organization (FAO).
Fat-free (defatted) soybean meal is a significant and cheap source of protein for animal feeds and many prepackaged meals; soy vegetable oil is another product of processing the soybean crop. For example, soybean products such as textured vegetable protein (TVP) are ingredients in many meat and dairy analogues. Soybeans produce significantly more protein per acre than most other uses of land.
Soy varies in growth and habit. The height of the plant varies from less than 0.2 to 2.0 m. The pods, stems, and leaves are covered with fine brown or gray hairs. The leaves are trifoliolate, having three to four leaflets per leaf, and the leaflets are 6–15 cm long and 2–7 cm broad. The leaves fall before the seeds are mature. The inconspicuous, self-fertile flowers are borne in the axil of the leaf and are white, pink or purple.
The fruit is a hairy pod that grows in clusters of three to five, each pod is 3–8 cm long (1–3 in) and usually contains two to four (rarely more) seeds 5–11 mm in diameter.
Soybeans occur in various sizes, and in many hull or seed coat colours, including black, brown, blue, yellow, green and mottled. The hull of the mature bean is hard, water-resistant, and protects the cotyledon and hypocotyl (or "germ") from damage. If the seed coat is cracked, the seed will not germinate. The scar, visible on the seed coat, is called the hilum (colors include black, brown, buff, gray and yellow) and at one end of the hilum is the micropyle, or small opening in the seed coat which can allow the absorption of water for sprouting.
Approximately 85% of the world's soybean crop is processed into soybean meal and vegetable oil. Soybeans can be broadly classified as "vegetable" (garden) or field (oil) types. Vegetable types cook more easily, have a mild, nutty flavour, better texture, are larger in size, higher in protein, and lower in oil than field types. Tofu and soy milk producers prefer the higher protein cultivars bred from vegetable soybeans originally brought to the United States in the late 1930s. The "garden" cultivars are generally not suitable for mechanical combine harvesting because there is a tendency for the pods to shatter upon reaching maturity.
Among the legumes, the soybean, also classed as an oilseed, is preeminent for its high (38–45%) protein content as well as its high (approximately 20%) oil content. Soybeans are the second-most valuable agricultural export in the United States behind corn. The bulk of the soybean crop is grown for oil production, with the high-protein defatted and "toasted" soy meal used as livestock feed. A smaller percentage of soybeans are used directly for human consumption.
Soybean seed contains about 19% oil. To extract soybean oil from seed, the soybeans are cracked, adjusted for moisture content, rolled into flakes and solvent-extracted with commercial hexane. The oil is then refined, blended for different applications, and sometimes hydrogenated. Soybean oils, both liquid and partially hydrogenated, are exported abroad, sold as "vegetable oil", or end up in a wide variety of processed foods. The remaining soybean meal is used mainly as animal feed.
Soybean meal is the material remaining after solvent extraction of oil from soybean flakes, with a 50% soy protein content. The meal is 'toasted' (a misnomer because the heat treatment is with moist steam) and ground in a hammer mill. Soybean meal is an essential element of the American production method of growing farm animals, such as poultry and swine, on an industrial scale that began in the 1930s; and more recently the aquaculture of catfish. Ninety-eight percent of the U.S. soybean crop is used for livestock feed. Soybean meal is also used in lower-end dog foods.
Soybean meal pellets are produced from ground soybean expeller or extraction meal by adding a suitable binder (e.g. 1 - 3% of molasses, fat or colloidal clays) and then pressing the composition under high pressure in pelletizing machines or extruders to form cylindrically shaped pellets. From a transportation standpoint, pellets generally have the same characteristics as the original plant residues, in particular in terms of the product's oil and water content. A distinction is drawn between expeller pellets and extraction meal pellets depending on their origin.
Oil content: 1.5 - 7.0%
Shipment / Storage
Soybean meal is shipped in bags or in bulk. The product has a greater tendency to heating and sweating than soybeans.
Note: See also advice on overseas shipment of Bulk Cargo, Solid Bulk Cargoes, Seedcake and Expellers and Extractions
Shipment / Storage
- Self-heating / Spontaneous combustion
- Toxicity / Hazards to health
- Insect infestation / Diseases