Processed meats are those meat products that are cured, smoked, or cooked. The microbiota most often associated with these products is listed in Table 5–1. The behavior of processed meats stored under vacuum or modified atmospheres is discussed in Chapter 14. Curing Although curing was used in ancient times as a means of meat preservation, it is employed now more for flavor and color development.
The classic meat cure ingredients are NaCl, nitrite or nitrate, and sugar (sucrose or glucose), with NaCl being the major ingredient. In addition to these, some products may contain curing adjuncts such as phosphates, sodium ascorbate or erythorbate, potassium sorbate, monosodium glutamate, hydrolyzed vegetable proteins, lactates, or spices. In dry curing, no water is added to the NaCl, nitrite or nitrate, and sugar mixtures.
In pickle curing, these ingredients are added to water to form a brine. Salt serves to prevent microbial growth during and after curing, and up to 2.5% may be found in finished products. Nitrite or nitrate serves to stabilize red meat color, contribute to cured meat flavor, retard rancidity, and prevent the germination of clostridial spores.
The isomers sodium ascorbate and erythorbate are used to stabilize color, to speed curing, and to make the cure more uniform. Since erythorbate is more stable than its isomer, its use is preferred, and it increases the yield of nitric oxide from nitrite and nitrous acid. At a level of 550 ppm, ascorbate or erythorbate reduces nitrosamine formation.
Sugar is involved in at least three curing functions: color stabilization, flavoring, and substrate for lactic fermentation. Also, it moderates the harsh flavor of NaCl. Corn syrups, molasses, or honey may be substituted for flavor.
Phosphates are used in most pumped meats (bacon, ham, roast beef, pastrami, etc.) to increase water binding. In curing brines, sodium tripolyphosphate is most commonly used, but a mixture of tripolyphosphate and sodium hexametaphosphate is used widely. See Chapter 13 for information on polyphosphates as antimicrobial agents.