Soybean is the richest plant source of protein. It contains 43 percent protein as compared to other legumes which contain 20 to 25 percent protein. Soy protein is also of the highest quality among all legumes.
Soybeans are high in fat, too. Most legumes (except peanuts) contain between 2 to 14 percent fat, whereas soybean contains 19 percent fat. At the same time, most of the fat in soybeans is unsaturated and beneficial.
3. High in Fiber
A serving of soybeans provides approximately eight grams of dietary fiber. However, some soy foods are processed in ways that decrease the fiber content significantly. Tofu and soymilk contain very little fiber, while soy foods that utilize the whole bean such as tempeh, soy flour and textured soy protein are high in fiber.
Soy foods are a good source of calcium in comparison to the commonly used legumes. Processing affects the calcium content of soyfoods considerably. Tofu due to its processing methods can contain between 120 and 750 mg of calcium per 1/2 cup serving.
5. Iron Source
Soya is rich in iron, too. However, both phytate and soy protein reduce iron absorption which leads to the iron in soyfoods being poorly absorbed. Iron could be better absorbed from fermented soyfoods like tempeh and miso.