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Cheese
One of our most versatile and
popular foods, cheese is used for everything from snacks and appetizers to
main courses and desserts. It's an ancient food that can be made from the
milk of almost any animal – cows, sheep, goats, yaks, camels, and buffaloes.
Most cheeses are made by adding a mixture of enzymes, known as rennet, to
milk to curdle it The main enzyme in rennet, which traditionally has
been isolated from the stomach lining of calves, is chymosin. Today, it can
also be produced by inserting the gene that codes for its production into
bacteria. This allows for a more ready production of chymosin and can also
cater to consumers who do not favor the idea of an animal extract in their
cheese. The liquid that remains after the curds have formed is known as
whey. When it is drained away, we are left with cottage or farmer's cheese.
Or the curds may be mixed with other ingredients, injected with special
molds or bacteria, soaked in wine or beer, pressed or molded, or smoked or
aged to make any of hundreds of different cheeses.
On average, it takes about 4 qt (3.8 liters) of milk to make 1 lb (450 g) of
Cheddar, Muenster, Swiss, or other firm cheese. A typical 1-oz (30-g)
serving of cheese contains 115 calories, about 200 mg of calcium, and 9 g of
fat. Cottage cheese has the fewest calories – about 90 in a half-cup
serving, but it has only half the calcium of milk. Cream cheese, Brie, and
other soft cheeses are comparable to hard cheeses in calories and fat, but
have less calcium.
Eat in Moderation Cheese is
rich in calcium and protein, making it a staple for vegetarians. But it's
also high in fat, cholesterol, and sodium. Most people – especially those
with a weight or cholesterol problem – should use it moderately, as an
occasional treat or garnish rather than as a staple food. Exceptions include
adolescents going through a growth spurt, vegetarians, and thin older women
threatened by osteoporosis, a weakening of the bones. Many people who cannot
digest milk because of lactose intolerance can eat cheese, especially the
hard ones; the bacteria and enzymes used to make cheese also break down some
of the lactose (milk sugar).
Health Hazards Doctors
often advise patients with heart disease, elevated blood cholesterol, or
high blood pressure to reduce the amount of cheese they consume. Because
most cheese is high in cholesterol and its fat is highly saturated, it
increases the risk of atherosclerosis, the clogging of arteries with fatty
deposits. And the sodium it contains can be a hazard for people with high
blood pressure.
Aged cheese can trigger a migraine headache in some susceptible people. The
likely culprit is tyramine, a naturally occurring chemical in Cheddar, blue
cheese, Camembert, and certain other ripe cheeses. Tyramine also interacts
with monoamine oxidase (MAO) inhibitors, drugs sometimes used to treat
depression, and can cause a life-threatening rise in blood pressure. People
taking MAO inhibitors should get a list of foods to avoid from their doctor.
People who are allergic to penicillin may react to blue cheese and other
soft cheeses that are made with penicillin molds. Also those who are
allergic to cow's milk may react to cheese, especially cottage and other
fresh cheeses. Cheeses made from goat's or sheep's milk are less likely to
be allergenic.
Pasteurized milk must be used to make commercial cheese in both the United
States and Canada. Occasionally, however, health-food stores and specialty
shops sell imported or homemade unpasteurized cheese. Such cheeses can
harbor dangerous salmonella and other bacteria; a case in point involved
several food-poisoning deaths in the United States that were later traced to
imported cheese made from raw milk.
Low-fat Cheeses Fat gives
cheese its rich texture and delicious taste, but it also adds calories and
cholesterol. About 70 to 80 percent of the calories in cheese comes from
fat. Even reduced-fat or part-skim milk cheeses can be high in fat; more
than 50 percent of the calories in part-skim milk mozzarella come from fat.
Historically, low-fat cheeses often lacked flavor, and tended to be high in
salt to improve flavor; sodium phosphate may be used to create a smoother
texture. today, there is a broader range of tasty low-fat cheeses on the
market. Cholesterol-free imitation cheeses are often made of soy, or tofu;
they still can be high in fat and sodium.
Fresh cheeses made from skim milk – for example, nonfat ricotta and cottage
cheese – are low in fat and calories. Whipped or blended versions of these
cheeses can be substituted for regular cream cheese, which is 90 percent
fat. Nonfat yogurt, strained through cheesecloth, is another possible
alternative. |
