Nitrates

In the past when we used salt with a higher nitrate content, we discovered that the meat had a different taste and color. Rock salts were mined in different areas of the world and exhibited different properties which depended mainly on impurities contained within. Take for example Himalayan salt that is sold on the Internet for cooking - it is pink. Potassium Nitrate was the main ingredient for making gun powder and it’s commercial name was saltpeter, still used today. Potassium Nitrate (KNO3-Bengal saltpetre) or sodium Nitrate (NaNO3- Chile saltpetre) were even added to water causing the temperature to drop and that method was used to cool wine in the XVI century. Nitrates and nitrites are powerful poisons and that is why the Food and Drug Administration established limits for their use. So why do we use them? The simple answer is that after testing and experiments, our modern science has not come up with a better solution to cure meats and prevent food poisoning. Only in the XIX century a German fellow Justinus Kemer linked food poisoning to contaminated sausages.

It took another 80 years to discover botulinum bacteria by Emile Pierre van Ermengem, Professor of bacteriology at the University of Ghent in 1895. The first scientific papers that explained the behavior of Nitrates were published only in the XX century so why had we been using Nitrates so much? Not to prevent botulism of which we had never even heard of before.

We had been and still are using Nitrates because:

What’s Better, Nitrate or Nitrite?

Both Nitrates and nitrites are permitted to be used in curing meat and poultry with the exception of bacon, where Nitrate use is prohibited. Sodium nitrite is commonly used in the USA (Cure #1) and everywhere else in the world. To add to the confusion our commonly available cures contain both nitrite and Nitrate.

Many commercial meat plants prepare their own cures where both nitrite and Nitrate are used. All original European sausage recipes include Nitrate and now have to be converted to nitrite. So what is the big difference? Almost no difference at all. Whether we use Nitrate or nitrite, the final result is basically the same. The difference between Nitrate and nitrite is as big as the difference between wheat flour and the bread that was baked from it. The Nitrate is the Mother that gives birth to the Baby (nitrite). Pure sodium nitrite is an even more powerful poison than Nitrate as you need only about ⅓ of a tea-spoon to put your life in danger, where in a case of Nitrate you may need 1 tea-spoon or more. So all these explanations that nitrite is safer for you make absolutely no sense at all. Replacing Nitrate with nitrite eliminates questions like: Do I have enough nitrite to cure the meat? In other words, it is more predictable and it is easier to control the dosage. Another good reason for using nitrite is that it is effective at low temperatures 36-40° F, (2-4° C), where Nitrate likes temperatures a bit higher 46-50° F, (8-10° C). By curing meats at lower temperatures we slow down the growth of bacteria and we extend the shelf life of a product.

When Nitrates were used alone, salt penetration was usually ahead of color development. As a result large pieces of meat were too salty when fully colored and had to be soaked in water. This problem has been eliminated when using nitrite. Nitrite works much faster and the color is fixed well before salt can fully penetrate the meat. Estimating the required amount of Nitrate is harder as it is dependent on:

Nitrates And The Law

Maximum in-going Nitrite and Nitrate Limits in PPM (parts per million) for Meat and Poultry Products as required by the U.S. Food Safety and Inspection Service

Curing Agent Curing Method
Immersion Cured Massaged
or Pumped
Comminuted
(Sausages)
Dry
Cured
Sodium Nitrite 200 200 156 625
Potassium Nitrite 200 200 156 625
Sodium Nitrate 700 700 1718 2187
Potassium Nitrate 700 700 1718 2187

The European Directive 95/2/CE (1995) allows 150 ppm of nitrite (if alone) or 300 ppm when combined (nitrite plus Nitrate), and the residual values should be less than 50 ppm (if alone) or 250 ppm (if combined). There are more stringent limits for curing agents in bacon to reduce the formation of nitrosamines. For this reason, Nitrate is no longer permitted in any bacon (pumped and/or massaged, dry cured, or immersion cured). As a matter of policy, the Agency requires a minimum of 120 ppm of ingoing nitrite in all cured “Keep Refrigerated” products, unless the establishment can demonstrate that safety is assured by some other preservation process, such as thermal processing, pH or moisture control. This 120 ppm policy for in going nitrite is based on safety data reviewed when the bacon standard was developed. Take note that nitrosamines can only be formed when products are heated above 266° F (130° C). This can only happen when cured bacon is fried or cured sausage is grilled. The majority of cured and smoked meats never reach such high temperatures.

There is no regulatory minimum in-going nitrite level for cured products that have been processed to ensure their shelf stability (such as having undergone a complete thermal process, or having been subjected to adequate pH controls, and/or moisture controls in combination with appropriate packaging). However, 40-50 ppm nitrite is useful in that it has some preservative effect. This amount has also been shown to be sufficient for color-fixing purposes and to achieve the expected cured meat or poultry appearance. Some thermally processed shelf-stable (canned) products have a minimum in-going nitrite level that must be monitored because it is specified as a critical factor in the product’s process schedule. By the time meats are consumed, they contain less then 50 parts per million of nitrite. It is said that commercially prepared meats in the USA contain about 10 ppm of nitrite when bought in a supermarket. Nitrite and Nitrate are not permitted in baby, junior or toddler foods.

Nitrate Safety Concerns

There has been much concern over the consumption of Nitrates by the general public. Studies have shown that when nitrites combine with by-products of protein (amines in the stomach), that leads to the formation of nitrosamines which are carcinogenic (cancer causing) in laboratory animals. There was also a link that when Nitrates were used to cure bacon and the latter one was fried until crispy, it helped to create nitrosamines. In order to accomplish that the required temperatures had to be in the 600° F (315° C) range. Most meats are smoked and cooked well below 200° F (93° C) so they are not affected. Those findings started a lot of unnecessary panic in the 1970’s about the harmful effects of nitrates on our health. Millions of dollars were spent, a lot of research was done, many researchers had spent long sleepless nights seeking fame and glory, but no evidence was found that when Nitrates are used within the established limits they can pose any danger to our health.

A review of all scientific literature on nitrite by the National Research Council of the National Academy of Sciences indicates that nitrite does not directly harm us in any way. All this talk about the danger of nitrite in our meats pales in comparison with the amounts of Nitrates that are found in vegetables that we consume every day. The Nitrates get to them from the fertilizers which are used in agriculture. Don’t blame sausages for the Nitrates you consume, blame the farmer. It is more dangerous to one’s health to eat vegetables on a regular basis than a sausage.

Nitrates in Vegetables

The following information about Nitrates in vegetables was published by MAFF, Department of Health and the Scottish Executive before April 1st 2000 when the Food Standards Agency was established. Number 158, September 1998. MAFF UK - NITRATE IN VEGETABLES: Vegetables contain higher concentrations of Nitrate than other foods and make a major contribution to dietary intake. A survey of vegetables for sale in supermarkets was carried out in 1997 and 1998 to provide up-to-date information on Nitrate concentrations, to assess the health implications for UK consumers and also to inform negotiations on a review of the European Commission Regulation (EC) No. 194/97 (which sets maximum levels for Nitrate in lettuce and spinach).

A study on the effects of cooking on Nitrate concentrations in vegetables was also carried out to provide further refinements for estimating dietary exposure. The vegetables were tested and the mean Nitrate concentrations found were as listed in the table on the right. For comparison the permissible amount of Nitrate in comminuted meat products (sausages) is 1718 mg/kg. If one ate 1/4 lb smoked sausage, the ingoing Nitrate would be 430 ppm. That would probably account for less Nitrates than a dinner served with potatoes and spinach.

In the 1920’s, the government allowed the addition of 10 lbs. of Nitrate to 100 gallons of water (7 lbs. allowed today). The problem was that only about one quarter of the meat plants adhered to those limits and many plants added much more, even between 70 and 90 pounds. There was no control and as a result the customer was eating a lot of Nitrates.

Vegatable Nitrate in mg/kg
spinach 1631
beetroot 1211
lettuces 1051
cabbages  338
potatoes  155
swedes  118
carrots   97
califlowers   86
brussel sprouts   59
onions   48
tomatoes   17

Cooking by boiling reduced Nitrate concentrations in most of the vegetables tested by up to 75 percent. Frying and baking did not affectNitrate concentrations in potatoes but frying caused increases in levels in onions. Dietary intakes of mean and upper range (97.5 percentile) consumers of these vegetables are 104 mg/day and 151 mg/day, respectively. These are below the Acceptable Daily Intake (ADI) for nitrate of 219 mg/day for a 60 kg adult set by the European Commission’s Scientific Committee for Food (SCF). There are therefore no health concerns for consumers. Ten years later in 2008 another British study concluded: “Our research suggests that drinking beetroot juice, or consuming other Nitrate-rich vegetables, might be a simple way to maintain a healthy cardiovascular system, and might also be an additional approach that one could take in the modern-day battle against rising blood pressure,” says Amrita Ahluwalia, PhD, one of the study’s researchers. Ahluwalia is a professor at the William Harvey Research Institute at Barts and The London School of Medicine.

How Much Nitrite is Dangerous

According to the report prepared in 1972 for the U.S. Food and Drug Administration (FDA) by Battele-Columbus Laboratories and Department of Commerce, Springfield, VA 22151 – the fatal dose of potassium Nitrate for humans is in the range of 30 to 35 grams (about two tablespoons) consumed as a single dose; the fatal dose of sodium nitrite is in the range of 22 to 23 milligrams per kilogram of body weight. A 156 lbs adult (71 kg) would have to consume 14.3 pounds (6.5 kg) of cured meat containing 200 ppm of sodium nitrite at one time. Taking into consideration that nitrite is rapidly converted to nitric oxide during the curing process, the 14.3 lbs amount will have to be doubled or even tripled. The equivalent amount of pure sodium nitrite consumed will be 1.3 g. One gram (1 ppm) of pure sodium nitrite is generally accepted as a life threatening dose.

As nitrite is mixed with large amounts of salt, it would be impossible to swallow it at least from a culinary point of view. Besides, our cures are pink and it would be very hard to mistake them for common salt.

The following information comes from the book “Meat Through the Microscope” written by C.Robert Moulton, Ph.D. and W.Lee Lewis, Ph.D. and published by Institute of Meat Packing, The University of Chicago:

Soaking reduced the curing agents in most of the sub-sections (sliced ham-our note) but especially in the butt and face sections. Smoking had little effect on the salt, nitrate and sugar content but the nitrite content was decreased. Baking reduced the percentages of all curing ingredients but the nitrite was so greatly reduced that the highest value found was only 11 parts per million. Table 66 gives the average composition of the five whole hams and shows clearly the effects of soaking, smoking and baking.

Effect of Operations on Composition of Hams

Stage Salt % Sugar % Nitrate %

Nitrite

p.p.m.

Water %
Out of cure 4.93 0.79 0.057 138 65
Soaked 4.60 0.72 0.048 115 67
Smoked 5.15 0.76 0.060 80 65
Baked 4.30 0.63 0.050 2 56

To emphasize the importance of these results, and especially of the very great destruction of nitrite by baking, one should remember in contrast that sweet-pickle solutions will contain from 500 to 1000 parts of nitrite per million and that the surface of hams removed from such pickles, especially at the ragged edges of the butt, will most certainly contain over 200 p.p.m. However, after soaking and smoking the average nitrite content is well within the prescribed limits. In the survey summarized above only two out of 10 surface sections showed over 200 p.p.m. of nitrite. In spite of the figures given in the first part of this paragraph, no subsection of surface meat showed more than 11 p.p.m. after baking.

By the time meats are consumed, they contain less then 50 parts per million of nitrite. It is said that commercially prepared meats in the USA contain about 10 ppm of nitrite when bought in a supermarket.

If we follow USDA recommendations, nitrates/nitrites are perfectly safe.