This is the process of preserving meat, often by smoking it. It can be applied to fish as well. Meat curing dates back before refrigeration was available and still has value today for its taste and food safety benefits.
The first step in making ham or bacon is curing the fresh pork by soaking it in a brine solution. The brine solution consists of water, salt, sugar (or other sweeteners), nitrite (or nitrate) salts, spices, and sodium erythorbate. Curing solutions generally call for 10–25% salt in weight compared to the weight of meat being cured; this requires 30-60 days when using dry salt and 3-9 days with wet brining. Brining is simply the process of adding salty water to meat.
The amount of nitrite is critical in curing meat since it is responsible for preventing botulism toxin formation by blocking the oxidation of essential taurine amino acid residues.
Normally, meat products contain very little nitrite except in the case of long-cured meats such as “prosciutto,” where salt and nitrates are added to enhance flavor under certain circumstances, color development occurs only with the addition of a starter culture containing “Clostridium botulinum” spores or by exposure to naturally occurring bacteria during processing. The mechanism starts with the conversion of sodium nitrate to sodium nitrite by the bacterial Nitrate reductase enzyme present on the cell surface . Sodium nitrite reacts readily with a variety of meat tissue components, forming cured meat pigment and adding flavor by meat cure process.
Nitrate and nitrite concentrations may be quantified in order to monitor compliance within industry guidelines or government regulations, ensure effective use of nitrate/nitrite additives due to potential health risks associated with excessive exposure, assist researchers in investigating new processes for curing meat, and help food manufacturers produce safe products.
Treatment of the meat with salt lowers the water activity in the meat product, making it inhospitable for bacteria. If raw meats are properly salted prior to cooking, then any bacteria present will be killed during cooking. The addition of nitrates and nitrites also reduces the likelihood that botulism-causing spores will survive in the final product. Additionally, sugar in a brine adds extra osmotic pressure, which inhibits bacterial growth. Sugar can replace part or all of the carbohydrate portion of a dry cure mix, such as dextrose (corn sugar), molasses (bagasse syrup), or lactose (milk sugar).