Nitrate, Nitrite, Nitrosamines

Derache, R. and Derache, P., 1999. Nitrate, nitrite, nitrosamines. I. Nitrate nutritional, toxicological and microbiological aspects. Microbio-... 

The carcinogenicity of nitrosamines has created widespread concern over the safety of food products that are significant sources of nitrates and nitrites. Nitrosamines are readily formed by reaction of secondary amines with nitrites at acid pH, conditions which may occur in the gastrointestinal tract. 

Nonvolatile Nitrosamines In Tobacco Smoke. Although there are more than 10 million exsmokers in the U.S.A., 53 million adults continue to smoke cigarettes and an additional 10 million still smoke cigars or pipes (39). The cigarette smokers are exposed to about 10 ng of volatile nitrosamines, 20-40 ng of NDELA and, most importantly, to 1-10 pg of tobacco specific N-nitros-amines with each cigarette smoked (Table IV). Similar quantities of the TSNA are found in sidestream smoke. The quantities of TSNA in the smoke are dependent on nitrate, nitrite, tobacco alkaloids and on NNN, NNK and NAT in the tobacco itself (31)>... 

Burton HR, Dye NK, Bush LP (1992) Distribution of tobacco constituents in tobacco leaf tissue, 1, Tobacco-specific nitrosamines, nitrate, nitrite and alkaloids, J Agric Food Chem 40 1050-1055 Burton HR, Dye NK, Bush LP (1994) Relationship between tobacco-specific nitrosamines and nitrite from different air cured tobacco varieties, J Agric Food Chem 42 2007-2011 Calafat AM, Polzin GM, Saylor J, Richter P, Ashley DL, Watson CH (2004) Determination of tar, nicotine, and carbon monoxide yields in the mainstream smoke of selected international cigarettes, Tob Control 13 45-51... 

Nitrate, nitrite Preservative Present in vegetables form carcinogenic nitrosamines... 

ELLEN G, EGMOND E, VAN LOON J W, SAHERTIAN E T and TOLSMA K, Dietary intakes of some essential and non-essential trace elements, nitrate, nitrite and N-nitrosamines by Dutch adults estimated by a 24-hour duplicate portion study , Food Additives and Contaminants, 1990 7 207-22. 

Okafor P.N., Nwogbo E., (2005), Determination of nitrate, nitrite, N-nitrosamines cyanide and ascorbic acid contents of fruit juices maijeted in Nigeria, African Journal of Biotechnology, 4(10), 1105-1108. 

Burton, H.R., N.K. Dye, and L.P. Bush Distribution of tobacco constituents in tobacco leaf tissue. 1. Tobacco-specific nitrosamines, nitrate, nitrite, and alkaloids J. Agr. 

A123. Pedersen, E. and I. Meyland Nitrate, nitrite, and volatile nitrosamines in pickled fish prepared by addition of nitrate Z. Lebensm. Unterforsch. 173 (1981) 359-361. 26A138. 

Peng Q (1990) Alkaloids, nitrates, nitrites and tobacco specific nitrosamines in dark tobacco. Masters thesis. University of Kentucky, Lexington, KY Severson RP, McDuffie KL, Arrendale RF, Gwynn GR, Chaplin JF, Johnson AW (1981) Rapid method for the analysis of tobacco nicotine alkaloids. J Chromatogr 211 111-121... 

Sodium Nitrate and Sodium Nitrite. Nitrates and nitrites ate used in meat-curing processes to prevent the growth of bacteria that cause botulism. Nitrates have been shown to form low, but possibly toxic, levels of nitrosamines in certain cured meats. For this reason, the safety of these products has been questioned, and use is limited (80). 

Inhibition of Nitrosamine Formation. Nitrites can react with secondary amines and A/-substituted amides under the acidic conditions of the stomach to form /V-nitrosamines and A/-nitrosamides. These compounds are collectively called N-nitroso compounds. There is strong circumstantial evidence that in vivo A/-nitroso compounds production contributes to the etiology of cancer of the stomach (135,136), esophagus (136,137), and nasopharynx (136,138). Ascorbic acid consumption is negatively correlated with the incidence of these cancers, due to ascorbic acid inhibition of in vivo A/-nitroso compound formation (139). The concentration of A/-nitroso compounds formed in the stomach depends on the nitrate and nitrite intake. 

In order to define the conditions of the growing cultures, buffered medium (VL) inoculated with E, coli ATCC 11775 and supplemented with nitrate, glucose and DMA was incubated at 37 C, and pH, nitrite concentration, nitrate concentration, cell growth and nitrosamine formation were followed (Fig. 1). Within 2 hrs, >90% of the nitrate is converted to nitrite (some of the nitrite is further reduced) and over 8 hrs the pH drops from 7.3 to 6.0. This would indicate that in experiments carried out for 20 hrs or more the control medium should be adjusted to pH 6.0 to 6.5 and nitrite should be added rather than nitrate. Such a control medium (VL) was supplemented with nitrite and DMA and NDMA formation was followed (Fig. 2). It can be seen that even without the addition of cells the rate of nitrosation is 4 fold greater than... 

N-Nitrosamines, formed principally from the reaction of naturally occurring secondary amines with nitrites that may be added to foods or produced by bacterial reduction of nitrates, have been identified in many food systems including cured meat products, nonfat dried milk, dried malt and beer. In addition, the presence of less volatile and non-volatile N-nitroso compounds or their precursors in foods have been suggested from a number of model system studies. 

In other working areas the reduction of airborne nitrosamines is possible, too. In a special curing process using a nitrite-nitrate salt bath for tube... 

N02 did not accumulate in lake sediments under conditions where nitrate rapidly disappeared. The low levels of both nitrite and nitrosatable amines in natural waters, along with expected third order kinetics fc make extensive nitrosamine formation unlikely. The prospect has been discussed by Dressel. ... 

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