Cured meats

C]-Urea Cure characteristics Cured meat Cured silicone LIM Cure rate... 

Meat color Meat curing Meat products... 

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). 

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. 

Nitrite is part of the preserving process for cured meats. Cigarette smoke contains high levels of nitrite. 

Both nicotinic acid and nicotinamide have been used in the enrichment of bread, flour, and other grain-derived products. Animal feed is routinely supplemented with nicotinic acid and nicotinamide. Nicotinamide is also used in multivitamin preparations. Nicotinic acid is rarely used in this appHcation. The amide and carboxyHc acid have been used as a hrightener in electroplating baths and as stabili2er for pigmentation in cured meats. 

Meat Products. Citric acid is used in cured meat products to increase the effectiveness of the antioxidant preservatives, as a processing aid, and a texture modifier. It is often encapsulated and released at a specific temperature from a controlled release matrix. 

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. 

NaN02 is used for diazotizing in dyestuff manuf, in org synthesis, rubber accelerators, prepn of nitric oxide, pharmaceuticals, photographic reag, curing meats, dyeing and printing textile fabrics, etc... 

Sodium nitrite can react with proteins in the stomach or during cooking, especially in high heat (such as frying bacon), to form carcinogenic N-nitrosamines. To prevent this, ascorbic acid or erythor-bic acid is commonly added to cured meats. 

During the curing process, some of the nitrites are converted to nitric oxide. This combines with the myoglobin proteins in the muscle of the meat to form the deep red nitric oxide myoglobin, which causes cured meats such as ham to turn pink during the smoking process. 

Sodium nitrate has been used for centuries to cure meat. Bacterial action during curing converts the sodium nitrate into sodium nitrite, which kills the bacteria that cause botulism, and combines with the myoglobin in the meat to form the pink color associated with ham. 

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

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. 

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. 

N-Nitrosamines in Cured Meats Other Than Bacon. The presence of N-nitrosamines in cured meats other than bacon has been the subject of several recent surveys (19,58,59). In general, the majority of the positive samples contained extremely low levels of N-nitrosamine, usually less than I yg/kg (19,58). This low level could, in part, be attributed to the discontinuation of the use of nitrite-spice premixes in the mid-l970 s (l 9). In the Holland study (59), the predominant N-nitrosamines detected were NDMA and N-nitrosomorpholine (NMOR) and, generally, values of 4 yg/kg were obtained for each N-nitrosamine. More correctly, these are presumptive N-nitrsoamine levels since mass spectral confirmation of their identities was not achieved. 

Results of a systematic study ( ) of food from the German market indicate the average daily intake for male persons amounts to l.l yg for NDMA and 0.1-0.15 yg for NPYR. Approximately 64% of this total daily intake for NDMA is found in beer, while another 10% comes from cured meat products. It is also important to note that food is not only the only source of N-nitrosamine or N-nitrosatable amines to which we are... 

A review by Bailey and Swain ( ) cited several references which indicated nitrite was responsible for cured meat flavor. These same authors presented chromatograms of volatiles from cured and uncured hams and while the chromatograms were similar, some quantitative differences led to the conclusion that the major difference due to nitrite was its reactivity to retard lipid oxidation. Greene and Price ( ) suggested, however, that sodium chloride was the major factor responsible for cured meat flavor rather than sodium nitrite or an absence of lipid oxidation. It has been concluded from other recent work (2) that nitrite was necessary to produce a typical ham aroma and flavor as well as to retard the development of off-odors and flavors during storage of cooked cured meat. 

Cytochrome c is a heme containing protein which occurs in muscle at lower concentrations than does myoglobin. It was demonstrated some time ago (18) that oxidized cytochrome c reacts with gaseous nitrite oxide to produce a nltrosyl compound. Recent work (19, 20, 21) has examined the reactions of cytochrome c with nitrite and the contribution of the product formed to cured meat color in considerably more detail. The general conclusion is that even at the pH normally encountered in meat, the reaction can take place in the presence of ascorbic acid but probably does not affect meat color because of the unstable nature of the reaction product and the low concentration. 

When the conditions of pH, temperature and concentration found in cured meat are considered, then the reaction rate is extremely slow. Evidence has also been given (41) that the reaction can occur while the tryptophyl residue is in the protein structure. 

Cured meats, bacon, ham, smoked sausages, beef, canned meat, pork pies, smoked fish, frozen pizza and some cheeses contain nitrate and nitrite additives, typically at... 

There is a balance to be drawn between risks. Looking at nitrite again, this ion has been used since the Middle Ages to preserve meat. It is the preservative in saltpetre which helps preserve cured meats and stop those who eat them getting botulism. There has been much research to find an alternative to nitrite as it can react with some amines to form carcinogenic nitrosamines. Risk analysis, reviewed in Chapter 4, is an important tool in controlling the use of additives. 

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