Meat curing nitrite

In meat curing, nitrite is traditionally used for developing the pink, heat-stable pigment. Its other important role is the inhibition of the outgrowth of Clostridium botulinum spores in pasteurized products and, in some countries, in several types of smoked fish. Nitrite also serves as an antioxidant and contributes positively to the development of the flavor of cured-meat. The undesirable side-effect, however, is the reaction of nitrite with amino groups of food constituents, leading to the formation of NNCs. 

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). 

Most nitrites are soluble in water and mildly toxic. Despite their toxicity, nitrites are used in the processing of meat products because they retard bacterial growth and form a pink complex with hemoglobin that inhibits the oxidation of blood (a reaction that would otherwise turn the meat brown). Nitrites are responsible for the pink color of ham, sausages, and other cured meat. 

PEGG R B, FISH K M and SHAHIDI F (2000) The replacement of conventional meat curing with nitrite-free curing system, Fleischwirtschaft, 80 (5) 86-9. 

In the last fifteen years there has been considerable interest in the analysis of volatile N-nitrosamines in foods. The primary focus has been on meat cured with nitrite (3 ) although nitrosamines have been shown to occur occasionally in other foods such as fish and cheese (, 3) Recently, attention has been directed to volatile nitrosamines in beer and other alcoholic beverages. The purpose of this paper is to review current information on the presence of nitrosamines in beer, and to discuss work done in our laboratory and elsewhere on the mode of formation of nitrosamines in beer. 

Meat curing, sodium nitrite in, 22 859-860 Meat Inspection Act, 18 683 Meat meal, 10 852 Meat products... 

Volatile nitroso compounds were determined in hams processed in elastic rubber nettings by SPE and GC-CLD577. By a similar method A-n i tro sodi ben zy lamine (278b), a semivolatile nitrosamine, was determined in these products by SPE followed by GC interfaced to a nitrosamine-specific TEA-CLD detector the coefficient of variation was 10.6% at the 2.1 ppb level578. The nitrosamines detected in ham most likely originate from the amine precursors in rubber and from the nitrite commonly used in the meat curing process. 

A correlation may be established between the concentration of oxidized lipids and the TEARS value, expressed as MDA equivalents, in uM units. Correction is due in some cases for the interference by dyes or other factors. For example, the presence of anthocyanins in red cabbage leaves or turbiditjf causes overestimation of lipid hydroperoxides in plant tissue by the TEARS method. TEARS was used to assert the level of endogenous peroxides in hypo- and hyperthyroidism, both conditions being characterized by low lipid and lipoprotein plasma levels and enhanced oxidative metabolism . In a procedure for determination of TEARS in edible oils, the sample is placed in a centrifuge at 12000 g before measuring at 532 nm (e = 1.56 x 10 M cm ) . A usual procedure for determination of TEARS in certain complex matrices involves steam distillation of the aldehydes responsible for the value, instead of extraction. In nitrite-cured meats, excess nitrite may cause nitrosation of MDA, thus interfering with distillation. To avoid this interference sulfanilamide is added, which is converted to a diazonium salt and... 

Although nittate was the traditional meat curing salt, Haldane (1901) demonstrated cured meat pigment development by addition of nitrite to hemoglobin. Hoagland (1908) concluded that bacterial or muscle tissue reduction of nitrate... 

In contrast to fresh muscle, meat has low levels of NAD (Madhavi and Carpenter, 1993). Thus, NAD-dependent enzymatic pathways for NOMb formation ate relatively unimportant in meat curing. In commercial practice, nitrite is reduced to NO by nonenzymatic means, including use of reductants such as ascorbate and erythorbate. Although meat has sufficient reducing ability to obtain a slow conversion of nitrite to NO, ascorbate or its isomer, erythorbate, is commonly added to curing brines or sausage emulsions to obtain faster NO production and thus a more rapid development of cured meat color. Care must be taken... 

Council for Agricultural Science and Technology (CAST). (1978). Nitrite in meat curing Risks and benefits. Report 74- Iowa State University, Ames, Iowa. 

In our search for nitrite alternatives, as far as flavor and oxidative stability Is concerned, we examined the effect of commonly used adjuncts In meat curing, as well as a large ntimber of antloxldant/sequesterant systems (40-42). In particular, the effect of sodium ascorbate (SA) and sodium tripolyphosphate (STFF) on the oxidative state of cooked meats was studied. These additives lowered the TEA numbers by a factor of about 2 and 4, respectively (Table IV). When used In combination, a strong synergism was observed. Furthermore, an Increase In the concentration of SA and/or STFF resulted In a decrease In the TEA values as depicted In Figure 6 (43). Addition of 30 ppm of butylated hydroxyanlsole (EHA) or tert-butylhydroqulnone (TEHQ) further reduced the TEA numbers and In fact the latter values were even lower than those obtained for meats treated with sodium nitrite (Table IV) (41). 

The rate of /V-nitrosation increases with the pKa of the amine and depends on the pH — it is highest at a pH range of 2-4. The reaction can be inhibited by compounds capable of binding the nitrosating agents — in meat curing, sodium ascorbate is very effective. Foods low in amines and nitrites generally contain about 1-10 ppb, while cured and heavy smoked meat and fish contain up to several hundred ppb of /V-nitroso compounds. 

L-Ascorbic acid Cupric sulfate anhydrous Potassium nitrate Sodium nitrate fixative, color poultry curing Potassium nitrite fixative, color red meat curing Potassium nitrite fixative, cosmetic creams/lotions Isocetyl stearate fixative, cosmetics Caprylic/capric/lauric triglyceride Caprylic/capric/linoleic triglyceride Isocetyl laurate Isocetyl myristate Methyl hydrogenated rosinate PEG-175... 

N-Nitrosamines are widely distributed in various human environments. The concern was initially focused on their widespread occurrence in food and consumer products, as beer, meats cured with nitrite, smoked fish, tobacco and tobacco smoke, rubber products including baby bottle nipples and pacifiers, cosmetics, drug formulations, or herbicides formulations. Much data of their occurrence have been obtained by inadequate analytical methods and must await confirmation. Considerable progress has been made in the development of adequate and specific methods for trace analysis of nitrosamines, and reliable information is expected in the near future. 

Diamond electrodes are useful for the detection of other electroactive anions, such as nitrite [30]. Nitrite is used in the manufacture of diazo dyes and other organic compounds, dyeing and printing of textile fabrics, and in meat curing and preserving processes. In recent years there has been increasing public concern about levels of the compound in processed foods. Exhaustive electrolysis revealed that the reaction proceeds as (30)... 

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