Nitrite cured meat

Concentration of different N-nitrosamines in nitrite-cured meat products is further increased following smoking processes. 

Various NOC can be found in food processing operations. The most commonly known contributors to dietary volatile and non-volatile N-nitrosamines are nitrite cured meats, particularly fried bacon and beer. Several reviews cover the occurrence and formation of... 

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... 

Iron bioavailability may be increased in the presence of meat (Politz and Clydesdale 1988). This is the so-called meat factor. The exact mechanism of this effect is not known, but it has been suggested that amino acids or polypeptides that result from digestion are able to chelate nonheme iron. These complexes would facilitate the absorption of iron. In nitrite-cured meats some factors promote iron bioavailability (the meat factor), particularly heme iron and ascorbic acid or erythor-bic acid. Negative factors may in-clude nitrite and nitrosated heme (Lee and Greger 1983). 

Lee, K., and J.L. Greger. 1983. Bioavailability and chemistry of iron from nitrite-cured meats. Food Technol. 37, no. 10 139-144. 

Our own work has shown a great decrease In the concentration of the volatiles In the cured, as compared to uncured, meats (Figure 5) (Ifi). The concentration of aldehydes originally present in cooked pork was reduced to < 12 of their original quantities (Table III, unpublished results). However, we did not Identify any new flavor active compound which could have been responsible for the cured flavor. Lipid oxidation, as measured by TBA number, was almost eliminated In cooked pork by adding nitrite at a level of 150 ppm (13.) Furthermore in preliminary evaluations, our untrained panelists were unable to differentiate amongst the flavor of nitrite-cured meats prepared from beef, chicken, mutton and pork (unpublished results). 

There is some evidence that inhibition of C. botulinum outgrowth in nitrite-cured meat products is mainly due to iron binding in such a way that this is no longer available for outgrowth of Clostridium spores. This strong binding also explains the antioxidative properties of nitrite in these products (Grever and Ruiter, 2001). 

A25. Dunn, B.P. and H.F. Stich Determination of free and protein-bound A-nitrosoproline in nitrite-cured meat products Food Chem. Toxicol. 22 (1984) 609-614. 

Okonkwo et al. (1992a,b) have discussed methods used to produce intermediate-moisture smoked meats. They prepared smoked beef by cook-soak/equilibrium in a solution containing sodium chloride, sodium nitrate, and potassium sorbate. Half of the samples were smoked for 18 hr (heavy smoking) and the other for 4 hr (light smoking) at 50°C. All samples developed the pink-red color of nitrite-cured meat. 

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