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Nutritional and Health Benefits of Soybeans
Soybeans contain all three of the macro-nutrients required for good nutrition:
complete protein, carbohydrate and fat, as well as vitamins and minerals, including
calcium, folic acid and iron.
Soybeans are the only common plant food that contain complete
protein. Soybean protein provides all the essential amino acids
in the amounts needed for human health. The amino acid profile
of soy protein is nearly equivalent in quality to meat, milk and
One Serving* of Soy
| Mature Soybeans (yellow), cooked
|| 1/2 cup (86 g)
| Soybeans, green (edamame)
|| 1/2 cup (90 g)
|| 1/2 cup (83 g)
| TVPâ, dry
|| 1/2 cup (47 g)
|| 1/4 cup (43 g)
| Tofu, firm
||1/2 cup (126 g)
| Soy flour, defatted
|| 1/4 cup (25 g)
||1 cup (245 g)
||2 Tbsp (34.5 g)
*Always check the nutrition facts label
of the product you purchase. Soymilk and tofu, for example, can
vary widely in nutrient content depending on the type and brand.
- Soybean Oil
- Soy Protein
- Soy Protein Products
- Soy Fiber
- Whole Soybean Foods
- Traditional Asian Soy Products
Soybean Oil - Nutritional Analysis
Soybean oil is 61% polyunsaturated fat and 24% monounsaturated
fat which is comparable to the total unsaturated fat content of
other vegetable oils (~ 85%). Like other vegetable oils, soybean
oil contains no cholesterol.
- Polyunsaturated vs Saturated Fats
Excessive intake of any fat is undesirable. Nutrition experts
recommend limiting total fat consumption to 30% or less of the
total daily calories and limiting saturated fats to 10% or less.
Saturated fatty acids raise blood cholesterol which can thicken
arterial walls and increase the risk of heart disease.
In both clinical trials and population studies, polyunsaturated
fats in the diet have been shown to actively lower serum cholesterol
levels (Hegstad et al., 1992).
Other research collected over many years from around the world
has shown that populations with diets low in saturated fats
have the lowest death rates.
As a result, the replacement of saturated fats with reasonable
amounts of polyunsaturated fats, such as those found in soybean
oil, is recommended.
- Essential Fatty Acids
Soybean oil is rich in polyunsaturated fatty acids, including
the two essential fatty acids, linoleic and linolenic, that
are not produced in the body. Linoleic and linolenic acids aid
the body's absorption of vital nutrients and are required for
human health. These two essential acids are also precursors
to hormones that regulate smooth muscle contraction, blood pressure,
and the growth of healthy cells.
Pure soybean oil is about 50% linoleic acid and 8% linolenic
- Hydrogenated Soybean Oil
Hydrogenation is used to solidify soybean oil for the manufacture
of margarine. This process increases stability of oils and to
raises the melting point of soybean oil shortening. Hydrogenation
changes the chemical composition and physical properties of
oils and affects the nutritional value. The degree of change
in nutritional value depends upon the amount of hydrogenation
necessary to produce the final product and the reduction of
polyunsaturates that occur.
The hydrogenation process also creates trans fatty acids
from cis unsaturates by rearranging hydrogens around the double
bonds in a monounsaturated or polyunsaturated fatty acid.
Soy Protein – Nutritional Benefits
Almost 40% of the calories in soybeans are derived from protein
causing soybeans to be higher in protein than other legumes and
many animal products. The quality of soy protein is highly notable
and approaches the quality of meat and milk. Unlike many other
good sources of protein, soybeans are low in saturated fat and
Soy Protein Products
Defatted soy flakes, a product resulting from the oil extraction
process of soybeans, are the basis of a variety of soy products
including soy flour, soy concentrates, and soy isolates.
- Defatted soy flours are about 86% protein and have very little
moisture. They contain no fiber, carbohydrates or fat. Soy flours
are very different from wheat flour and can not be substituted
directly fro all the wheat flour in a recipe. Replacing about
15% of the wheat flour with soy flour gives a nutty flavor,
darker crust, and moister crumb.
- Soy concentrates contain about 65% protein and retain most
of the soybean's dietary fiber. Concentrates also add texture
and help foods retain moisture.
- Soy isolates contain about 90% protein and are the most versatile
of all the soy protein products. Isolates are used to add juiciness,
cohesiveness, and viscosity to a variety of meat, seafood, and
poultry products. Soy isolates are the chief component of many
dairy-like products, including cheese, soymilk, infant formula,
non-dairy frozen desserts and coffee whiteners. They are used
to add texture to meat products and are valued for their emulsifying
properties. Soy isolates absorb five times their weight in water.
Isolates can be used to enhance both the nutritional quality
and taste of meat products. This is especially true for soy
used to enhance the flavor and nutritional quality of tough
meat. Soy isolate is excellent for improvement of sensory attributes
of whole meat products. Roasts and hams that contain soy isolates
are juicer and more nutritional. Soy isolates can also be used
as an ingredient to supplement or replace milk powder. In addition,
isolates are commonly used in dairy products such as beverages,
frozen desserts and imitation cheeses.
Soybeans, especially the outer hull, are an excellent source
of dietary fiber (6 grams fiber per 1 cup cooked soybeans).
During processing, the soybean hull is typically removed. This
extracted hull can be further process to create a fiber additive
for breads, cereals and snacks.
Soybeans contain both soluble and insoluble fiber. Soluble fiber
may help lower serum cholesterol and control blood sugar. Insoluble
fiber increases stool bulk, may prevent colon cancer, and can
help relieve symptoms of several digestive disorders.
Whole Soybean Foods
- Full fat flour is made from whole soybeans and therefore has the
same fat, protein and dietary fiber content as the whole bean. Full fat flour
is used for doughnut
mixes, pie crusts, pancake batters and other baked goods.
- Soymilk is made from ground soybeans that
are mixed with water to form a milk-like liquid. Soy milk can
be consumed by people who are dairy sensitive or by strict vegetarians
who eat no animal proteins. Soymilk is an excellent source of
protein, B-vitamins and iron, and if fortified, provides adequate
calcium. It has low levels of saturated fat and no cholesterol.
Traditional Asian Soybean Foods
For centuries, soybean have been mainstays of healthy diets throughout
Asia and the East. today, Asian whole soybean foods are slowly
gaining acceptance in the West as a unique source of nutrition
that can help reduce saturated fat in the diet.
Whole soybean foods are high in protein, fiber and unsaturated
fat, and rich in vitamins and minerals. They also show many anticarcinogenic
properties related to the unique benefits of soy isoflavones,
phytochemicals which exert biological effects in humans and other
- Tofu (soybean curd) is a bland, cheese-like
cake formed from soymilk by adding a coagulant (typically calcium
sulfate) to the milk to form curds that are shaped and pressed
into cakes. Depending on the coagulant used, tofu is rich in
minerals and is an excellent source of high-quality protein,
polyunsaturated fats (including linoleic and linolenic acids)
& B vitamins. Versatile and nutritious, tofu can be used
in soups, salads, pastries, sandwiches, and spreads. It can
also be used as an alternative to yogurt or soft cheese.
- Miso is a thick, high-protein paste made from soybeans, salt and
a fermenting agent (usually an Aspergillus oryzae mold culture), that is
similar in taste
and color to soy sauce. Sometimes a grain, such as rice and barley, is fermented
with the soybeans for additional flavor. Miso is popular as a soup and breakfast
drink in Japan.
- Natto is made of fermented, cooked whole soybeans, and offers nutritional
values similar to those found in miso. It has a sticky, viscous coating and
with a cheesy texture. It is used as a spread or in soups.
- Tempeh is made of whole, cooked soybeans infused with a culture
to form a dense, chewy cake. It is a good source of fiber protein, polyunsaturated
fats and lecithin,
as well as useful amounts of calcium, iron, magnesium, potassium, and some
- Soybean sprouts are rich in vitamins A, B and C, and are eaten
raw in salads
- Soy sauce is the most widely recognized soybean
food. Soy sauce is fermented for about 18 months as a mixture
of whole soybeans, wheat flour, and fermenting agents, such
as yeast. The resulting liquid is extracted and processed. Soy
sauce adds sodium and flavor to foods.