What... is it sick?
Merely twenty years ago, many of the pathogens of greatest concern today, were not even recognized as causes of food borne illness! These include the infamous campylobacter jejuni, escherichia coli O157:H7, listeria monocytogenes, cyclospora cayetanensis
, and others. The Center For Disease Control estimates that each year in the United States alone, food borne diseases cause approximately 76 million illnesses, 325,000 hospitalizations, and 5,000 deaths. Three nasty pathogens in particular, (Salmonella, Listeria, and Toxoplasma
), are responsible for 1,500 deaths annually.
, a common bacteria in soil and sea sediments, is a rod-shaped microorganism first recognized and isolated in 1896 following an incident involving the poisoning of several people having eaten bad ham. Clostridium botulinum is an obligate anaerobe
meaning that oxygen is poisonous to its cells. However, due to the enzyme superoxide dismutase
, its cells tolerate small traces of oxygen. Although it can only reproduce in an anaerobic environment, when it does, it produces the deadliest poison known to man - botulinum toxin
. Ingested, one millionth of a gram will close your eyes permanently!
In comparison to cyanide, botulinum toxin is 500,000 times more toxic! Additionally, it is relatively quick. Symptoms of botulinum toxic poisoning include nausea, stomach pain, double vision and spreading paralysis ultimately reaching the respiratory organs and the heart. Is it absolutely fatal? If the dose is low and a patient receives treatment quickly, about half of those affected may survive, although recovery may require months or even years. Fatalities occur annually, especially in countries where home canning is popular. Fortunately, the risk of acquiring botulism is very low although the microorganism`s spores are exceptionally persistent and resistant to freezing, heating, smoking, and drying. Worse, in contaminated food, there is no foreign taste or odor. Ideal temperatures and conditions for growth are 70° - 95° F. (20° - 35° C.) in an atmosphere of no oxygen, pH above 5, and salinity below 10%... conditions not unlike those found in cured sausages! Why then, has man survived over the ages?
Sodium Nitrate and Sodium Nitrite Cures
Anciently, most probably by accident, man discovered that when salt was added to meat, it improved its flavor, color, and shelf life. Then somewhere in time, sodium nitrate came into use as a naturally occurring contaminant of salt. Chile and Peru have massive deposits of sodium nitrate (NaNO3). Not to be confused with sodium nitrite (NaNO2), the substance is also found in leafy green vegetables. Acting as powerful antioxidants, nitrates and nitrites reduce oxidative rancidity. However, when added directly to meats, sodium nitrite is primarily responsible for the inhibition of pathogen growth including that of clostridium botulinum - the bacteria causing botulism poisoning. Nitrate in itself is not successful in producing the curing reaction.
How Does It Work?
Sodium nitrate must be reduced by lactic acid bacteria (micrococcaceae species
) or other natural means to be effective. In other words, nitrate breaks down into nitrite - and nitrite breaks down into nitric oxide (not to be confused with nitrous oxide)
/ It is the nitric oxide that actually cures meat. Modern science has not produced a substitute for sodium nitrate or sodium nitrite used as agents to preserve meat and destroy clostridium botulinum
. As these salts are poisonous used in proportionately greater amounts, companies have continually tried to improve upon them though their efforts have been futile.
is used to cure all meats that require cooking, smoking, and canning. This includes poultry, fish, hams, bacon, luncheon meats, corned beef, pates, and many other products. Cure #1 in the United States, contains 6.25% sodium nitrite and 93.75% sodium chloride (salt). As this formula contains no sodium nitrate, there is no waiting for nitrate to be broken down into nitrite. It is effective immediately in curing meat. In manufacturing the cure, one ounce of sodium nitrite is added to each one pound of salt. When used in the curing process, only 4 ounces of cure is added to 100 pounds of sausage. Two level teaspoons will cure 10 lbs. of meat.
Note that in other countries, the formula varies. In the United Kingdom, suppliers offer Prague Powder # 1 (Cure #1) with 5.88% sodium nitrite, the remainder being salt.
is used in dry-cured (fermented) sausages where curing time allows the nitrate to gradually break down into nitrite. Cure #2 in the United States, contains 6.25% sodium nitrite, 4% sodium nitrate, and 89.75 sodium chloride (salt). Why so much nitrate? (Remember, it is actually nitrite reducing to nitric oxide that cures meat). After two weeks dry-curing, only about a quarter of the 6.25 % sodium nitrite remains in the meat. Nitrite is simply too fast. In salamis requiring three or more months to cure, a certain amount of sodium nitrate must be added to the recipe to break down over time. Since micrococcaceae species bacteria are inhibited at low pH, sausages relying on nitrate reduction must be fermented by a traditional process. Therefore, nitrate is still used by many dry sausage manufacturers because nitrate serves as a long time "reservoir" of nitrite. Note that in other countries, the formula varies. In the United Kingdom, suppliers offer Prague Powder # 2 (Cure #2) with 5.67% sodium nitrite, 3.62 sodium nitrate, the remainder being salt.
Potassium Nitrate (Saltpeter)
Saltpeter is 100% potassium nitrate (KNO3). Although it is used in various cures throughout the world, it is no longer included in cures in the United States (with the exception of only a few applications) as it is thought to produce cancer-causing nitrosamines when cooked at higher temperatures. Commercially, with only a few exceptions, it has been banned by law in America since 1975. A fatal dose of potassium nitrate is merely 30 grams. Sodium nitrite will cancel your clock at only about 22 milligrams per kilogram of body weight. You can plainly see why these cures MUST be handled correctly.
Use meat cures with caution.
Nitrates and nitrites must be used with caution and good sense, although it makes no sense to become paranoid while handling the stuff. Simply use good judgment and don`t mix it if you`ve been drinking alcohol. Both nitrates and nitrites are considered toxic in larger amounts and for that reason, strict limits on their use have been established. Usually, the amount of added sodium nitrite lies in the range of 50-200 mg. per kg and sodium nitrate in the range of 200 to 600 mg. per kg. Both cures have been formulated so that 1 (one) level U.S. teaspoon will cure 5 pounds of meat. It is always a good idea to weigh the cure for best accuracy. Dissolving the cure into a little water ensures adequate uniform dispersal throughout the meat
Notice that formula #1 contains only nitrite while formula #2 contains both nitrite and nitrate. One curing agent must never be confused with the other within any recipe and one certainly must not be substituted for the other. If you mix, cure, and smoke sausage, or cure and smoke hams, it becomes your responsibility to follow directions mixing exactly four ounces Prague Powder with one hundred pounds of meat, or for us home consumers, precisely two level teaspoons mixed with a little water for even distribution, for each ten pound batch of sausage. If you are mixing only five pounds of sausage, add just one level teaspoon of curing salt. Always remember that any recklessness in mixing these salts may potentially injure someone. Measure twice - mix once! Incidentally, the product known as Tender Quick* contains 0.5 sodium nitrite, 0.5 sodium nitrate, salt, sugar, and propylene glycol (for brined meats).
How much is dangerous?
In humans, a fatal dose (consumed in a single dosage) of potassium nitrate (saltpeter) is about 30-35 grams (about two tablespoons). A single fatal dose of sodium nitrite is about 22 or 23 milligrams per kilogram of body weight. One gram (1 ppm) of pure sodium nitrite (in a single dose of about 1/3 teaspoon) is life threatening. The amount of sodium nitrate needed to be fatal is about 1 teaspoon. Modern cures containing sodium nitrite and/or sodium nitrate mixed with a large amount of salt are dyed bright pink in order to make it distinct and difficult to confuse with anything else. Another way of looking at the potentially dangerous level of properly distributed nitrite in food is to realize that it would require about 20 lbs. of cured meat to be consumed during a single meal by an average person to impose any real harm, even though merely a third of a teaspoon taken "straight up", is considered enough to be fatal.
The strength of nitrates and nitrites themselves do not vary. It is the amount added to a sodium chloride (salt) carrier that makes a cure stronger or weaker in comparison to others. Again, note that in the UK, nitrited salt cures vary in strength and one MUST look at the label to be safe. In Sweden, folks call their product Colorazo at 0.6% nitrite. In France, it`s Sel nitrite` at 0.6% nitrite. In Poland, they call their nitrited salt cure Peklosol at 0.6% nitrite, and in Germany, it is Pokelsalz at 0.6% nitrite content in salt. As you can see, Prague Powder Cure #1 in America is ten and a half times stronger than European cures, with the exception of some of those in the UK.
Expiration of nitrite?
The United States Army recommends that the Cures be used within seven years although there has been no evidence of deterioration when Prague Powder is kept dry and out of direct light.
Many people have the wrong perception of "chemical" cures. They are simply salts - salts that break down into another composition called a "reduction". When NaNO3 (sodium nitrate) is placed into meat, it eventually begins to react with the staphylococcus
bacteria present in meat. The reaction creates NaNO2 (sodium nitrite) - the reduction needed (nitric oxide) in the presence of oxygen to start the curing process.
However, if the meat does not contain adequate numbers of staphylococcus
to begin with, the curing process will become very much restrained. In this case, NaNO2 (sodium nitrite) is added directly to the meat without having to endure the reductive process. It goes to work almost instantly, immediately beginning the curing process.
Often, meats brined in chlorinated water will have their naturally-present staphylococci
reduced by the chlorine. Hence, very little reaction will take place to reduce NaNO3 to NaNO2. To insure safety, sodium nitrite is often added directly to meat to remove the risk of insufficient numbers of reductive bacteria.