Nitrate in cured meats

The nitrate-nitrite intake from natural sources is much higher than that from processed foods. Fassett (1977) estimated that the nitrate intake from 100 g of processed meat might be 50 mg and from 100 g of high-nitrate spinach, 200 mg. Wagner and Tannenbaum (1985) reported that nitrate in cured meats is insignificant compared to nitrite produced endogenously. Nitrate is produced in the body and recirculated to the oral cavity, where it is reduced to nitrite by bacterial action. 

Oliveira, S. M., T. I. M. S. Lopes, and A. O. S. S. Rangel. 2004. Spectrophotometric determination of nitrite and nitrate in cured meat by sequential injection analysis. J. Food Set. 69 C690-C695. 

Food Additives Contaminants Committee (1978). FACC Report Review of Nitrites and Nitrates in Cured Meats and Cheese, HMSO, London. 

Nitrates are found in fairly high concentrations in beets, spinach, kale, coUards, eggplant, celery, and lettuce. AdditionaHy, nitrates and nitrites are commonly used in the curing solutions of bacon, ham, and other cured meats. In cured meats, nitrates and nitrites control the growth of microorganisms, particularly Clostridium botulinum, and also serve as color preservatives. 

NaN02, in addition to its use with nitrates in heat-transfer molten-salt baths, is much used in the production of azo dyes and other organo-nitrogen compounds, as a corrosion inhibitor and in curing meats. 

These days, sodium nitrite replaces most of the sodium nitrate used in cured meats, except for that used in slow-cured country ham. 

A U.S. patent was issued in 1917 for the use of nitrite as a replacement for nitrate in curing brines (Doran, 1917, as cited in Binkerd and Kolari, 1975). Kerr et al., (1926) found that hams cured in a brine containing about 2000 ppm sodium nitrite were equivalent in flavor and color to hams cured with nitrate. The maximum nitrite level found in any part of the hams was 200 ppm. Based on these experiments, the U.S. Department of Agriculture (USDA) in 1925 authorized use of sodium or potassium nitrite in curing brines in federally inspected establishments, at 0.25 to 1 ounce per 100 pounds of meat, such that the finished product would contain no more than 200 ppm sodium... 

Pierson, M. D., and Smoot, L. A. (1982). Nitrate, nitrite alternatives, and the control of Clostridium botulinum in cured meats. Grit. Rev. Food Sci. Nutr. 17, 141-187. 

Use Oxidizing agent solid rocket propellants fertilizer flux glass manufacture pyrotechnics reagent refrigerant matches dynamites black powders manufacture of sodium salts and nitrates dyes pharmaceuticals an aphrodisiac color fixative and preservative in cured meats, fish, etc. enamel for pottery modifying burning properties of tobacco. 

A number of nitroso compounds, A-nitrosamines among them, are potent carcinogens. The most common carcinogenic nitrosamines, found mainly in protein food, are A-nitroso-dimethylamine (NDMA), A-nitroso-diethylamine (NDEA), A-nitroso-pyrrolidine (N-Pyr), and A-nitroso-piperidine (N-Pip). These compounds supposedly increase the risk of colon, rectum, stomach, pancreas, and bladder cancers. Nitrosamines are most prevalent in cured meats, but have also been detected in smoked fish, soy protein foods dried by direct flame, and food-contact elastic nettings. Dietary surveys indicated weekly mean intakes of these compounds amounting to about 3 pg per person (Anon., 1988 Cassens, 1995). In addition, the precursors of nitrosamines, especially nitrate, are abundant in some leafy and root vegetables (Table 14.1). 

Nitrates and nitrites are spread within environmental, food, industrial, and physiological systems. Nitrate may be reduced by bacteria to nitrite, and nitrite produces carcinogenic nitrosamines. Nitrite is also commonly employed in cured meat products to provide antimicrobial action, color fixation, and preservation. Nitrite can oxidize hemoglobin iron(II) to iron(III) resulting in methemoglobin, leading to a condition known as methemoglobinemia in children mainly. In excess, nitrates and nitrites may be toxic. 

There is also concern that nitrites from food may produce nitrosoamines when they react with amines in the presence of the acid found in the stomach. In 1976, the FDA reduced the permissible amount of nitrite allowed in cured meats from 200 parts per million (ppm) to 50-125 ppm. Nitrites (and nitrates that can be converted to nitrites by bacteria) also occur naturally in many foods. 

Vegetables are not the only source of nitrate intake. Potassium and sodium salts of both nitrate and nitrite are commonly used in food industry, in curing meat, for fixing the color, for inhibiting the microbial growth, and for obtaining the characteristic flavor. ... 

Sodium nitrate (1885) n. NaNOs. A deh-quescent crystalline salt used as an oxidizing agent, a fertihzer, and in curing meat. 

The nitrate and nitrite used in cured meats appear to have little effect on rancidity in the small concentrations in which they are used and at pH values within the normal range of meat (Lea, 1939 Watts and Lehmann, 1952b). 

P.E. Jackson, P.R. Haddad and S. Dilli, Determination of nitrate and nitrite in cured meats using high-performance liquid chromatography,/. Chromatogr., 295, 471, 1984. 

Sofos, J.N., Busta, F.F. and Allan, C.E. (1979) Botulism control by nitrate and sorbate in cured meats a review. J. Food Protect. 42, 739-770. 

The determination of nitrite in mineral water and in cured meat samples was performed using a glassy carbon electrode modified with a film of tetraruthenated cobalt porphyrin [51], associated with an FIA configuration. With this modified electrode, the anodic process was anticipated (working potential maintained at -1-0.75 V rather than -1-1.0 V) and a 15-fold current enhancement was verified with respect to results observed with the unmodified working electrode. By incorporating a copper-cadmium column before the amperometric detector and in the FIA manifold, it was possible to succeed the quantification of nitrate in the same samples. 

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