Meat curing antioxidant effects

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. 

Thus, antioxidant effects of nitrite in cured meats appear to be due to the formation of NO. Kanner et al. (1991) also demonstrated antioxidant effects of NO in systems where reactive hydroxyl radicals ( OH) are produced by the iron-catalyzed decomposition of hydrogen peroxide (Fenton reaction). Hydroxyl radical formation was measured as the rate of benzoate hydtoxylation to salicylic acid. Benzoate hydtoxylation catalyzed by cysteine-Fe +, ascorbate - EDTA-Fe, or Fe was significantly decreased by flushing of the reaction mixture with NO. They proposed that NO liganded to ferrous complexes reacted with H2O2 to form nitrous acid, hydroxyl ion, and ferric iron complexes, preventing generation of hydroxyl radicals. 

Kanner, J., Harel, S., Shagalovich, J., and Berman, S. (1984). Antioxidative effect of nitrite in cured meat pnxlucts Nitric oxide-iron complexes of low molecular weight. ]. Agric. Food Chem. 32, 512-515. 

Muscle tissues contain a multi-component antioxidant system consisting of lipid-soluble compounds (a-tocopherol, ubiquinone), water-soluble compounds (ascorbate, histidine-dipeptides) and enzymes (superoxide dismutase, catalase, glutathione peroxidase). Lipid oxidation in meats can be effectively controlled by the use of various phenolic compounds derived from spice extracts, by vitamin E supplementation of animal diets, and by processing of cured meat with sodium nitrite. Various natural antioxidant formulations containing mixtures of tocopherols, ascorbyl palmitate and citric acid show synergistic effects in stabilizing cooked and frozen meat. Synthetic antioxidants, BHA, TBHQ, propyl gallate (see Chapter 9) and combinations with citric acid, ascorbic acid or phosphates are also effective formulations used to retard lipid oxidation in... 

Developing alternatives to nitrite is extremely difficult because of its many functions in food including its antimicrobial effect against C. botuli-num, its role in the formation of the characteristic colour of cured meats, its antioxidant activity that prevents the formation of off-flavours and its contribution to the characteristic flavour and texture of cured meats. 

Curing prevents WOE. Myoglobin is stabilized by nitrite, therefore, no additional non-heme iron is formed during cooking (Table 12.18). In addition, the MbNO formed has an antioxidative effect (cf. 12.3.2.2.4). Lipid peroxidation does not occur and new aroma substances are formed that are characteristic of cured meat. 

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. 

The problem of getting the antioxidant into tissue fat has not been adequately solved. The most effective phenolic inhibitors are practically insoluble in water. Attempts at utilizing them in meat generally involve either their solution in a fat which is then applied to the surface of meat cuts or their dispersion with various carriers and emulsifying agents in curing brines, cooking waters, and comminuted meats. 

Several vitamins have some desirable additional effects. Ascorbic acid is a dough improver, but can play a role similar to tocopherol as an antioxidant. Carotenoids and riboflavin are used as coloring pigments, while niacin improves the color stability of fresh and cured and pickled meat. 

Escudero, E., Aristoy, M.C., and Nishimura, H., et al. (2012) Antihypertensive effect and antioxidant activity of peptide fractions extracted from Spanish dry-cured ham. Meat Sci 91, 306-311. 

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