Soybean oil is extracted from the soybean (Glycine max) and often has a dark yellow or faint green color. Standard vegetable oil is typically composed of soybean oil.
The first domestic use of soybean is traced to the eastern half of North China in 11th BC, or perhaps a little earlier. Soybean is one of the five main plant foods of China, along with rice, wheat, barley, and millet. Early accounts have it that soybean production was localized in China until after the China-Japan War of 1894 to 1895, when the Japanese started to import soybean oil cake as fertilizer.
Soybean shipments to Europe were made in around 1908, although Europeans had been aware of soybeans as early as 1712 through a German botanist's writing. In U.S. literature, the first use of the word "soybean" was in 1804. Most of the early U.S. soybeans were used as a forage crop instead of being harvested for seed.
Today, Americans consume more than 28 billion pounds of edible oils annually, and soybean oil accounts for about 65 percent of the said figure. Mexico and Korea are large customers of U.S. soybean oil. Unfortunately, about half of the soybean oil used in the country is hydrogenated, as soybean oil is too unstable to be used in food manufacturing.
Among the problems with partially hydrogenated soybean oil is trans-fat and the health hazards of the soy itself, as well as the prevalence of genetically engineered soybeans today.
Soybean oil is processed and sold mainly as a vegetable oil, while the remaining soybean meal is typically used as animal feed. It is also the primary source of biodiesel in the country, making up 80 percent of domestic production.
Lecithin is a product extracted from soybean oil, and it is a natural emulsifier and lubricant used in many foods and commercial and industrial applications. It helps keep the chocolate and cocoa butter in a candy bar from separating, and is used in pharmaceutical products and protective coatings.
Soybean oil is commonly used to make mayonnaise, salad dressing, margarine, and non-dairy coffee creamers. It is a usual feature of processed foods, which is where the problem begins: processed foods are perhaps the most damaging part of most people's diet, contributing to the occurrence of disease and poor health.
Partially hydrogenated soybean oil is one of the primarily culprits in processed foods, alongside high fructose corn syrup (HFCS). Used alone or in combination, they spell trouble for your wellness. But why is there a need to hydrogenate oil?
One of the most common answers you hear is that it prolongs the oil's shelf life. For example, raw butter is likely to go rancid far more quickly than margarine does. Hydrogenation — where hydrogen gas is forced into the oil at high pressure — also makes the oil more stable and increases it melting point, allowing it to be useful in various food processing methods that use high temperatures.
In the late 1990s, experts started to see and confirm the adverse health effects of this chemical alteration. Beware, though, that "fully hydrogenated" is different from "partially hydrogenated." The latter contains trans-fat, while the former does not. But this does not make fully hydrogenated soybean oil a healthful choice.