Soybeans are the most cultivated legume in the world, with a long history in China. The popularity of soy products is increasing, and a wide variety are available on the market today. Soybeans grow in pods and can be green, yellow, brown or black. They are high both in protein and carbohydrates, as well as other nutrients.
The protein in soybeans is considered a complete protein, having the essential amino acids in the correct amounts. This makes them more nutritious protein sources than other beans and legumes, closer to the proteins in animal products.
In Oct. 1999, the U. S. Food and Drug Association, or FDA, recommended 25 g of soy protein daily as part of a low-cholesterol, low-saturated fat diet, to reduce the risk of heart disease.
The protein in soybeans can vary by type and preparation method. A half-cup of cooked soybeans contains 16 g of protein and a half-cup of roasted soybeans has 39 g protein. There are approximately 10 g of protein in 1 cup of plain soymilk, 13 g in 4 oz. of firm tofu and 9 g in 4 oz. of silken or soft tofu, according to The Minnesota Soybean Research & Promotion Council.
The carbohydrates in soybeans are called complex carbohydrates, the kind found in legumes, starchy vegetables and whole grains. Soybeans are also a good source of indigestible fiber carbohydrates. Carbohydrates are an important source of energy for your body, metabolized into glucose during digestion. There are 19.89 g of carbohydrates in 1 cup of cooked, green soybeans and 56.28 g of carbohydrates in 1 cup of dry roasted soybeans, according to the USDA Agricultural Research Service Nutrient Data Lab.
Soybeans are used whole as a vegetable called edamame. They are also roasted and served as a snack food. Whole soybeans are used to make soymilk by crushing them with water and adding sugar and flavorings. Soybeans are also used to make traditional foods such as tofu, tempeh, miso soup and soy flour.
Some people have allergies to soybeans and soy products. Be sure to check with your doctor if you have allergies to foods before adding soybeans.