Soak “fresh” dried soybeans as directed on the package and then discard the water.
If you use canned beans, discard the liquid in the can and rinse the beans in cool running
water. In discarding this liquid you are getting rid of some of the soluble indigestible sugars
that may cause intestinal gas when you eat beans.
What Happens When You Cook This Food
When soybeans are cooked in liquid, their cells absorb water, swell, and eventually rupture,
releasing pectins, gums, and the nutrients inside the cell. In addition, cooking destroys
antinutrients in beans, making them safe to eat.
How Other Kinds of Processing Affect This Food
Tofu. Tofu is a bland white cheeselike food made of liquid squeezed from soybeans and
stiffened with a firming agent such as gluconolactone, calcium chloride, or calcium sulfate.
Heating tofu evaporates moisture and further coagulates proteins, making the tofu
firmer and more dense. Tofu can be frozen; defrosted tofu is caramel-colored rather than
creamy white with a spongy texture that soaks up sauce and flavorings.
Tofu is a useful cholesterol-free vegetarian substitute for meat, fish, or poultry. One
3-ounce serving of tofu equals one meat serving on the USDA/Health and Human Services
Food Guide Pyramid. One four-ounce serving of regular tofu has one gram dietary fiber, six
grams fat (0.9 g saturated fat), 10 g protein, 130 mg calcium, and 70 mg isoflavones.
Soy milk. Soy milk is a blend of soy flour (ground soybeans) and water. It is not a natural
source of calcium, but most commercial soy milks are calcium-fortified, a useful alternative
for people who cannot eat dairy foods. One cup calcium-fortified soy milk may have as
much as 300 mg calcium.
Soy sauce. Soy sauce is made by adding salt to cooked soybeans and setting the mixture
aside to ferment. Soy sauce is high in sodium, and it may interact with monoamine oxi-
dase (MAO) inhibitors, antidepressant drugs that inactivate naturally occurring enzymes
in your body that metabolize tyramine, a substance found in many fermented foods such
as soy sauces. Tyramine is a pressor amine; it constricts blood vessels and increases blood
pressure. If you eat a food containing tyramine while you are taking an MAO inhibitor,
you cannot effectively eliminate the tyramine from your body, and the result may be a
hypertensive crisis.
Milling. Soy flour is a powder made from soybeans. It is high in protein (37–47 percent). It can
be used as a substitute for up to 20 percent of the wheat flour in any recipe. Unlike wheat flour,
it has no gluten or gliadin, which makes it useful for people who have celiac disease, a meta-
bolic disorder that makes it impossible for them to digest these wheat proteins (see flour).
Canning. The heat of canning destroys some of the B vitamins in soybeans. Since the B
vitamins are water-soluble, you could save them by using the liquid in the can. But the liquid
also contains the indigestible sugars that cause intestinal gas when you eat beans.
Soybeans