Nitrates in meat products

Follett, M.J. and Ratcliff, P.W. (1963) Determination of nitrite and nitrate in meat products. Journal of the Science of Food and Agriculture 14, 138-144. 

Oztekin, N., Nutku, M. S., and Erim, F. B., Simultaneous determination of nitrite and nitrate in meat products and vegetables by capillary electrophoresis. Food Chem., 76,103, 2002. 

A similar approach was used by Ferreira et al. (1996) for the simultaneous assay of nitrite and nitrate in meat products. The system was based on splitting the flow after injection and the subsequent confluence of it before reaching the detector, allowing the reduction of nitrate to nitrite online in part of the sample plug. Each channel had a different residence time, therefore separate peaks where obtained for nitrite and nitrite + nitrate. The same system was later used by Pinho et al. (1998) for the evaluation of nitrite and nitrate contents in 15 different brands of pate. 

Meat processing Determination of the N02" /N03 ratio in meat products, of nitrate in the water being used... 

Another useful application of CE is the determination of the preservative nitrate and nitrite ions in meat products. It is known that nitrite causes methaemoglobinaemia and, with secondary and tertiary amines, yields the carcinogenic nitrosoamines. Owing to these toxic effects, it is important to develop new analysis methods for the simultaneous determination of the two anions reducing the matrix effect in meat samples. The method developed was based on the separation of the two anions in a capillary coated with polyethyleneimine (PEI). Since PEI is a cationic polymer, the EOF is reversed over a wide pH range and the fast separation of anions is achieved without the addition of any electroosmotic modifier to the Tris separation buffer at pH 7.5. The LODs of the method for nitrite and nitrate were 0.10 ttg/mL and 0.09 ttg/mL, respectively. ... 

The determination of nitrite and nitrate in meat and sausage products is an important problem, because their tolerated concentrations are strictly limited. Sample preparation includes homogenization of the sample, its extraction with a 5% borax buffer in a hot water bath, and subsequent Carrez precipitation with 15% potassium hexacyanoferrate(II) and 30% zinc sulfate solution. 

In the field of ion chromatography, solid-phase extraction is frequently used for the preconcentration of analytes from samples with an organic matrix, e.g., solvents, fruit juices, body fluids, or for the determination of nitrate and nitrite in meat products. ... 

In the ion chromatographic analysis of meat products, a number of constituents elute close to the void volume of the anion exchanger used, so Interferences cannot be excluded. Because chloride concentrations in meat products can easily exceed nitrite and nitrate concentrations by a factor of 5000, UV detection at low wavelengths (207-225 nm) is usually applied. At those wavelengths, chloride absorption is usually very low. Siu and Henshall [372] described an alternative extraction method, which requires neither protein precipitation nor extraction with SPE cartridges. According to this method, 10 g of sample is mixed with... 

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). 

Sodium nitrate is also used in formulations of heat-transfer salts for he at-treatment baths for alloys and metals, mbber vulcanization, and petrochemical industries. A mixture of sodium nitrate and potassium nitrate is used to capture solar energy (qv) to transform it into electrical energy. The potential of sodium nitrate in the field of solar salts depends on the commercial development of this process. Other uses of sodium nitrate include water (qv) treatment, ice melting, adhesives (qv), cleaning compounds, pyrotechnics, curing bacons and meats (see Food additives), organics nitration, certain types of pharmaceutical production, refining of some alloys, recovery of lead, and production of uranium. 

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. 

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. 

Potassium nitrite is an antidote to cyanide poisoning. It also is a vasodilator. An important application is in the dye industry to prepare diazonium salts and azo dyes. Another use is in curing certain meat products where the salt imparts an appetizing pink color to cured meats and retards microbial growth on the meat. The commerical product is usually a nitrite-nitrate mixture, containing 85% KNO2 and 15% KNO3... 

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... 

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