Soybeans are legumes that grow throughout much of the world and constitute one of the world's major food crops. They are turned into a wide array of foods, including tofu, miso, soymilk and tempeh. Soybeans have been in use as a food crop in Asia for as long as history has been recorded, but didn't make their way to the United States until the 19th century. In the modern world, the vast majority are either turned into oil or used as feed for livestock. There are two major types cultivated these days: the yellow and black varieties. There is no significant nutritional difference between the two.
There are a number of different ways soybeans may be prepared for human consumption. They may be eaten sprinkled with salt and boiled, in a form usually referred to by the Japanese name edamame. They may be turned into soymilk, a process involving soaking them in water, then grinding them and boiling them into a milky substance. The curds from this soymilk may then be pressed into blocks of tofu, in a process similar to that of making cheese from dairy milk. Whole soybeans may also be cooked slightly and then fermented using vinegar and the fungus Rhizopus oligosporus to make tempeh. The leftover soy flour from extracting the oil is also used to create textured vegetable protein (TVP), which is often used in meat substitutes.
The health benefits and concerns of soybeans are hotly debated by leading nutritionists and medical professionals. They contain a full range of amino acids and a high protein content, making them an ideal supplemental source, particularly for vegetarians and vegans. Many people hold that soy should not be fed to infants in any form, as it may lead to allergies, but this is contested by other experts.
Soybeans are also one of the most genetically-modified crops, with a full 80% of those grown on Earth having undergone some sort of modification. The most famous of these modifications is the Roundup Ready soybean, which can be sprayed with the weed-killer and survive. Their genetically-modified status is a cause of concern for many who tout its health benefits and believe genetically modified foods to have possible health risks. For this reason, many soy products proclaim that they use non-GMO (genetically-modified organism) soybeans.
Over 100 million metric tons of soybeans are produced globally each year, with the United States as the number one producer. Argentina and Brazil also play a large role in their production, and there is concern that their increased use of land to cultivate the legumes threatens the rainforest.