Soybean facts

Soybean or soya bean is a species of legume (Glycine max) native to eastern Asia. It is classified as an oilseed rather than a pulse due to its high oil content and its more popular use as a source of vegetable oil and industrial applications such as biodiesel. It has been grown in China for over 5000 years.

Soybean is one of the most versatile crops grown around the world. It has a raft of applications including a source of vegetable oil for human food and industrial uses, as a valued protein source in livestock production, for use in preparing a range of human foods such as traditional foods like tofu and soy milk as well as novel uses as a protein isolate and for textured protein. Soybean also has an almost endless application in industrial products such lubricants, plastics, waxes and a range of intermediate chemicals including fatty acids. And in more recent times, soybean has been recognised for its health and well being properties and is now used in a range of nutrition bars, cereals, pasta and baked goods.

Soybeans make up about 60% of the overall world oilseed production. Soybeans are grown and traded across the globe and are considered one of the most important of global commodities. Of the average 260 million tonnes used worldwide each year about 10% is used directly for human foods, about 20% is extracted for oil and the remainder is used for livestock feeds.

The wild ancestor of soybeans is Glycine soja (previously known as Glycine usseriensis), a legume native to central China. Soybean has been used in China for over 5000 years as a food and a component of many drugs and medicines. In 2853, the Chinese Emperor Shennong proclaimed soybean as one of the five sacred plants; soybeans, rice, wheat, barley and millet. However, rather than as a food crop, soybean was considered sacred for its use in crop rotation as a method of fixing nitrogen back into the soil and the benefits this provided to future crops. The soybean would be ploughed back in as a green manure and the field prepared for food crops. Cultivation of soybeans was long confined to China, but in the first millennium AD, China exported soybeans to many parts of Asia, including Korea, Japan, India, Malaysia, Indonesia and the Philippines.

As a food source, soybeans were first used to produce fermented products such as soy sauce, tempeh, natto and miso. Fermentation was used to remove the high phytoestrogen content of soybeans. While it is generally claimed that this was their only use until recent times, there is historical evidence of soy milk and tofu being produced as early as 80AD.

Soybeans were first introduced into Europe and then the United States in the early 1700s, where they were used primarily as an industrial crop. It wasn’t until the 1920’s that soybeans as a food crop was recognised by western culture and soybeans are now grown globally on every continent except Antarctica. World soybean production is approximately 230 million tonnes per annum and leading producers are the United States, Brazil, Argentina, China and India.

Soybeans are consumed both directly as human food products and processed into meal and oil for use in both for human food and animal feed applications.

Consumption of soybeans as a food is largely concentrated in Asia, particularly China, Japan and Indonesia, and are either used directly as a whole seed or are processed and incorporated as a high protein ingredient into food like tofu, tempeh, soy milk, soy cheese or other products. While this accounts for a relatively small percentage of the overall market (6%), it is still significant in volume terms, and particularly, value.

The vast majority (85%) of soybeans are processed into soybean meal and oil. Approximately 98% of soybean meal is further processed into animal feed, with the balance used to make soy flour and proteins. Of the oil fraction, 95% is used in edible applications, with remainder used for industrial products such as fatty acids, soaps and biodiesel.

Traditional soybean foods 

Uses of Soybean Meal for Animal Feed (Author: Sarah Willis)

Soybeans are considered by many agencies to be a source of complete protein. A complete protein is one that contains a significant and balanced source of essential amino acids, which are required by animals daily due to the body’s inability to synthesise them itself. Soy protein is recognised as a good source of protein and as a quality alternative to meat, eggs and milk protein. For this reason soybeans are valued by not just vegetarians and people who cannot afford meat, but also health conscious individuals looking to an alternative to meat proteins.

Soybeans typically contain about 40% protein, 20% oil and 35% carbohydrates. Soy oil is the major food product used worldwide and after extraction the protein is used as a valued meal for livestock. However the protein is also used in soy foods requiring high temperature processing such as tofu, soy milk and textured vegetable proteins.