Nitrate is a salt of nitric acid and found naturally in fruits, vegetables and grains. It is also added to cured meats such as salami, bacon and hot dogs as a color preservative and to retard the growth of microorganisms. Foods that are naturally rich in nitrates can provide a variety of health benefits, but some nitrate is converted to nitrite in your body, which can form nitrosamines and cause negative effects.
Nitrate is an essential plant nutrient found in soil that is taken in by all plants and used as a primary nitrogen source. As such, nitrate is a natural part of all vegetables, fruits and cereals to varying degrees. Industrial fertilizers also contain nitrates and some of their residues can be found on the outside of fruits and vegetables. This issue is mitigated somewhat under organic management as nitrogen commercial fertilizers are not allowed.
Nitrates are naturally occurring chemicals present in soil, air, surface waters and ground waters. Nitrogen and oxygen combine to form the nitrate compound (NO3-), using three oxygen atoms and one nitrogen atom. A nitrate should not be confused with a nitrite (NO2-) which is formed from two oxygen atoms and one nitrogen atom. In nature, nitrates can easily be converted to nitrites and vice versa. Human exposure to nitrates and nitrites comes from water, food and air.
Just as nitrites and nitrates are found naturally in our environment, foods such as beets, celery, radishes and spinach are natural sources of nitrite and nitrate in our diet. Nitrates may also be found in some fish and dairy products such as cheese.
Nitrites are added to meat products during processing for two reasons:
Nitrites may be added directly to the meat product, but more frequently nitrates are added. The nitrates are converted to nitrites through natural bacterial fermentation and chemical reactions in the meat. Cured meat products have sodium or potassium nitrate (nitrate salts) added to them to preserve the meat product and prevent the growth of the bacterium Clostridium botulinum. C. botulinum can produce spores and causes botulism, a potentially deadly food borne illness. Nitrites are used in pork, beef and poultry products to enhance colour. For example, nitrates are added to ham and bacon, giving them their characteristic pink colour. Some countries (but not Canada) permit the use of nitrites in fish products.
Cultured celery powder contains preformed nitrites produced by bacterial action on nitrates present in the celery product. The level of preformed nitrites present in the celery powder must be declared by the manufacturer of the cultured celery powder. The producer of the meat product must determine the amount of cultured celery powder to be included in the formulation to achieve the minimum levels of nitrites (100 ppm, Meat Inspection Regulations, 1990) needed to cure the product without exceeding the maximum allowable limit (200 ppm, Food and Drug Regulations).
Some scientific studies suggest that nitrites promote and induce cancers in animals. When nitrites combine with certain amino acids, N-nitroso compounds or nitrosamines are formed and these have been shown to be carcinogenic (cancer-causing). In response to these findings, and the concern that excess nitrate/nitrite may react with the protein in the meat when it is cooked, to form these compounds, Health Canada has limited the amount of nitrate or nitrite that can be added to meat products to 200 parts per million (ppm). A complete ban on the use of nitrates and nitrites in foods has not been implemented because of the beneficial uses as preservatives and particularly their prevention of Clostridium botulinum growth. There is also some scientific evidence suggesting that low levels of nitrates and nitrites (below 200ppm) pose no health concern. Clear Creek Organic products are required to have 100 ppm. Clear Creek Organics uses vegetable products to introduce nitrate into our processed meats. Celery juice and celery powder appear to be highly compatible with processed meat products as celery has very little vegetable pigment and a mild flavour profile that does not take away from the finished product flavour.
The nitrate and nitrite exposure we receive from air is negligible. Our primary source of exposure to nitrates and nitrites is through the food we consume, however exposure to these compounds can also occur through drinking water.
“Fortunately, fundamental research on nitric oxide has become one of the most active research areas in biology because nitric oxide has found to play critical roles in several physiological functions in living organisms. For example, in skeletal muscle, nitric oxide appears to interact with protein such as the ryanodine receptorcalcuim release channel and regulates muscle functions such as excitation-contraction coupling, blood flow, respiration and glucose homeostasis.” (Stamler and Meisssner, 2001)
“ It is generally accepted that less than 5% of human consumption of nitrate and nitrite is due to meat products. The majority of nitrates consumed are from vegetable products. “(Archer, 2002)
Unique ingredients in organic processed meats such as sea salt derived from evaporation of sea water, unrefined without addition of free-flow additives and retains the natural characteristic of the source. (Kuhnlein, 1980; Heinerman and Anderson, 2001). While sea salt has been suggested as a likely source of nitrates, limited analytical information suggested that the nitrate content of sea salt is relatively low.
The second most common ingredient observed in organic processed meat ingredient lists is raw sugar, most often evaporated sugar cane juice. It appears there is no evidence of significant nitrates or nitrite concentration in the raw sugar.