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Sodium Nitrate
Chemical Formula: NaNO3
Sodium Nitrate is a SALT - also known as "salt-peter" - (which, if you watched the original Star Trek, you will know is used to make gunpowder!)
MODERN USES: Used in pickling meats, in the manufacture of glass and matches, as a fertilizer, and in enamels in pottery glazes.
Curing meat by using a salt brine was a widely used method of preserving meat for hundreds of years before the days of refrigeration. A typical
traditional brine recipe for curing beef or ham might be:
100 pounds of fresh pork meat
5 gallons water
8 pounds of regular salt (sodium chloride)
2 pounds brown sugar
2 Ounces salt-peter (sodium nitrate)
"Dry curing" is also done with this "classic" 8-2-2 recipe, omitting the water, of course, and rubbing the salt, sugar and sodium nitrate into the
meat by hand.
Fully-cooked brine-cured hams are generally what you find in the meat cases at the market, and if smoked, they are lightly-smoked. Smoked hams are
generally considered more flavorful. The smoking process affects not only the flavor, but also aids in aging. The longer aged, the more flavorful the
ham. Some are aged up to two years! Curing and smoking are two separate operations, however. A ham which had not been properly cured could not be
preserved by smoking alone.
Salt and sugar both "cure", that is preserve, meat by osmotic action. Osmosis is the action whereby the liquid in the meat absorbed into the salt,
or sugar. In addition to somewhat dehydrating the meat by drawing the water from the food, they dehydrate and kill the bacteria that make food spoil.
Sugar is also a natural tenderizer, and tends to ameliorate the toughening effect of the drying process.
Sodium nitrate (NaNO3) and its close relative sodium nitrite (NaNO2) are preservatives that you find in processed meats. Salami, hot dogs, pepperoni,
bologna, ham, bacon, Spam, etc. all contain sodium nitrate as one of the ingredients. So, no matter where you buy your meats and cold cuts, if it is
cured meat, there will be some amount of sodium nitrate present.
There are two reasons for adding these salts to meats. First, of course, they act as a preservative. They inhibit botulism, and the meat "keeps"
longer. They also preserve the color of the meat (meaning that it looks pink, like ham, rather than gray, like cooked hamburger). You have probably
noticed that nearly all cured meats remain pink or red even though they are cooked during processing.
The jury is out on how harmful these substances are. Although there are those vigilantes out there that love to spread the "warning", it is not
clear that these salts are any more harmful than any other food eaten in
moderation.
Sodium nitrite (nitrIte, *not* nitrAte) reacts with stomach acid and other chemicals in the stomach to produce nitrosamines, which have been shown to
cause cancer in animals when consumed in very LARGE quantities. (where have we heard that before??)
However, there's not really all that much sodium nitrate/nitrite in meats and we consume sodium nitrite/nitrate from other foods as well, so it is not
at all clear that they are harmful in the quantities we get from meats.
The most "harmful" aspect, from the point of view of someone who is dieting is that cured meats generally contain some amount of sugar, as you can see
from the recipe above. Salts in general retain water, cause bloating, can raise your blood pressure and slow weight loss.
Chemicals usually are tested for an ability to cause cancer by feeding HUGE dosages to small numbers of rats and mice. As some may recall from the
saccharine studies, the equivalent of literally POUNDS of the substances are fed to the animals. Thus, concentration of the chemical in the body is
artificially heightened to severely abnormal levels. This is not in any way indicative of the way in which any of us, even the most gluttonous, out of
control binge eater, would eat.
In any food study done, there are, realistically, only a small number of animals that can be used (a few hundred is considered a big study) and this
is tiny compared to the U.S. population of close to 300 million. This would be comparable to saying that the reactions of a few hundred randomly
selected humans is the "common" reaction of all humans. And we know how inaccurate that is...
When an artificially huge dosage causes cancer in some of their test animals, researchers will then tell us that a smaller amount would also
cause cancer, but less frequently, and then proceed to tell us that we
humans will have the same thing happen to us. They are, then, generalizing the results across species, and making inferences regarding dosages. Yet,
how accurate is it to say that a rat, heavily loaded with a particular chemical is going to react like a human, who eats a minute amount of that
substance? Researchers defend their methods by saying that their results can be "generally" indicative of a "trend". Unfortunately, rats and mice
are not exactly like humans, and in some tragic cases, rodents may be less
sensitive than people to a particular chemical (as happened so tragically with thalidomide), or react differently than humans, (such as happened with
saccharin).
Because they can't test thousands of animals, or perform human tests, though, the standard high-dosage cancer test on small numbers of rodents is
considered the only practical way to identify food additives that might cause cancer.
The salting and curing of meat can be traced into antiquity, but already by the close of the 19th Century scientists had discovered that nitrite was the
required component for killing bacteria and that it reacted with the meat pigment myoglobin to produce the characteristic cured color.
At the beginning of the twentieth century there was a movement to have the
government ensure that our food supply be as safe as possible. One result was the Federal Meat Inspection Act in 1906. The regulations governing
curing were issued in 1926, following a good deal of experimentation by USDA into the methods and results of curing ham. Basically, it was allowed to add
one-quarter ounce (156 ppm) of nitrite to one hundred pounds of meat. Interestingly and with the exception of some changes in the bacon
regulations, the same rules are in force today, some seventy years later. This fact alone substantiates the strong safety record for cured meat.
When nitrite is added to meat in the curing process it is "used'. It reacts with or is bound to various constituents of the meat such as the protein
pigment responsible for color. For example, if 156 ppm is added only about ten to twenty percent of it is analytically detectable following the heat
processing.
By the close of the decade of the 1970's the National Academy of Sciences issued two reports which in essence indicated that nitrite cured meat was
safe for humans. The detection of nitrosamines, suspected to be cancer causing, was found to be extremely low, and the government started a
monitoring program which is still ongoing today.
The industry took the option of lowering the amount of ingoing nitrite to approximately 50 ppm, thereby decreasing the potential for formation of
nitrosamines. The use of reducing agents such as ascorbates was also shown to greatly reduce the risk, and they were used to the maximum.
Other work demonstrated that the residual nitrite in cured meat contributed only a fraction to the total body burden of nitrite in humans. It is
discovered that nitrite is actually generated by the body, all by itself, in
human saliva, for example, and that nitrate is also formed naturally in green or root vegetables. As a matter of fact it is now known that nitric
oxide is important to the human body.
Recent work (Cassens, 1997) has shown that modern cured meats contain about 10 ppm of nitrite, a substantial reduction from the level used in the 1970's
of 50 ppm. They also found that considerable ascorbates remain in cured meats, and this offers strong protection against nitrosation reactions.
Epidemiological studies in 1994 and again in 1996 seemed to implicate wiener (hot dog) consumption with childhood cancer, and gave as the reason the
residual nitrite content of the meat. These studies have been criticized because they were based solely on recall data (memory of reporting
individuals) of what the individuals consumed, rather than on actual physical testing.
Eating huge amounts of any one food is not good for you. We know that. I don't care if you're talking ham, or the fruit you grew on a tree lovingly
tended in your backyard. You need a varied diet, period. Cured meat is not going to kill you from eating an occasional ham dinner, or grabbing a few
slices of salami for a snack.
Again, I reiterate - the most "harmful" aspect I can see, from the point of view of someone who is dieting is that cured meats generally contain some
amount of sugar - carbs you don't need, and can set off cravings. Also, salts in general retain water, cause bloating, can raise your blood pressure and
can slow weight loss.
Final word - use moderation.
By Lisa M. Alekna
© 4/11/00
References used:
Salt curing in brine , 1996
Al Durtschi
According to Smoky, 1999
© C. Clark Hale
Safety of Cured Pork Products, 1999
© Author: Dr. Robert G. Cassens, Univ. of Wisconsin,
Reviewer: Dr. Roger Mandigo, Univ. of Nebraska
How Stuff Works, 1999
© By Marshall Brian
Chemical Cuisine:CSPI's Guide to Food Additives, 1999
© By Andrew Cutting and Doug Pierce
The Meat Smoking and Curing FAQ, 1996
© Maintained by: Richard Thead
Ham It Up! - by Peggy Trowbridge
© 2000 About.com, Inc.
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