Originally from Asia, soya, just like beans or peas, is a leguminous plant. The soya plant is an erect, hairy plant from 0.6 to 1.5m (2 to 5 ft) in height, with large trifoliate leaves, small white or purple flowers, and short pods with one to four seeds. On maturity, reached between 100 to 150 days after planting, depending on variety, location and weather, the leaves turn yellow and drop, and the pods rapidly become brown and dry.

The soya bean: good quality protein

The seeds of the soya plant, almost spherical in shape, are usually light yellow, but some varieties are black, brown or green. They have a black, brown or yellow hilum (seed scar) and are an excellent source of good quality protein and compares well with other protein foods. The soya bean contains about 38% protein, 18% oil, 22% dietary fibre of which 11,9% soluble and 10,1% insoluble and 14% other components (a.o. moisture, minerals and vitamins).
Soya bean oil is rich in polyunsaturated fatty acid and contains no cholesterol. Soya beans are also a good source of calcium, iron, zinc, phosphate, magnesium, B vitamins and folate. All eight essential amino acids are found in soya bean protein, which are necessary for human nutrition and are not produced naturally in the body.

The various kinds of soya

The genetic variation within the same species is enormous. There are thousands of varieties of soya including 'red', 'black' and 'green'’. The most popular variety is the 'yellow' soybean (Glycine max), which belongs to the family of the papilionaceous. The varieties can also be classified in geographical areas: Indian, Japanese, Manchurian and Chinese. The Manchurian and Japanese have high fat content, whereas the Chinese and Indian are characterized by high protein content.