Soybean oil

Soya plant & soybean

Soybean oil (also known as oleum soyae) is obtained as a co-product from the soybean. In the legume family (Leguminosae or Fabaceae), the soybean belongs to the subfamily of the papilionaceous plants (Faboideae). Due to its high protein content, the soya plant also belongs to the protein plants. The soybean is an annual herbaceous plant with brownish hairs. There are different varieties of the soya bean. High-growing varieties can reach a height of up to 2 meters. Most common, however, are upright growing varieties with a height of 20 to 80 centimeters. The green, thin stems are fine and densely haired. Soybeans have pronounced taproots up to 1.5 meters long. The soya plant lives in symbiosis with nitrogen-collecting nodule-bacteria that adhere to the roots of the plant. This is typical for the papilionaceous family. The term "nodule-bacteria" comes from the fact that the bacteria form small nodules on the roots. These are able to bind atmospheric nitrogen and make it available to the plant by converting it into high-quality protein. This favourable characteristic means that there is no need for artificial nitrogen fertilization of soya fields.

The green leaves are three to five in number with ovoid leaflets. They are also hairy on the edge and on the underside. Even as the soybeans ripen, the plant shed its leaves. The flowers of the soya plant are short-stalked, white or purple, self-pollinating and can be seen for about 3 to 4 weeks. It takes about five months from sowing to harvest. As fruits, the plant forms 3 - 5 cm long, brown-yellow hairy pods with usually 2 - 3 internal beans. Depending on the variety, these are white, yellow, green, brown or purple to black. The different varieties are distinguished by their level of ripeness, sizes, types, colours, oil content and intended use. Yellow seed kernels are used in oil production. Still unripe, green or yellow seed kernels are consumed as vegetables. Brown and black seeds are often used as animal feed. Soybean fields are brown and bare when harvested, because towards the end of the growing season the leaves of the plant wilt and fall off before the beans are ripe. The seeds contained in the pods have a protein content of between 35% and 50%, making them the grain fruits with the highest protein content. The oil content of the beans ranges between 15 and 21%.

The soya bean (Glycine max) is a subtropical plant but is now also cultivated in tropical climates and regions with a moderate climate. The plant therefore thrives best at high temperatures and, especially in the beginning, with plenty of water.