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Brining, curing, pickling
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Objective
Brining and curing is a process whereby a product is treated with common salt (NaCl) to which one or more curing salts may be added. The preservation of food, esp. vegetables, by lowering the pH is called pickling. The objectives of brining, curing and pickling are the longlife preservation of the quality, control of the growth of spore forming microbes, a decrease in the energy needed for heat treatment, and to add to the taste of the product.Field of application
Brining and curing are applied in the production of certain types of cheese, meat, fish and vegetables (e.g. sauerkraut). Salt levels in the product can range from 1 to 5%. Cucumber, tomatoes and some other garden vegetables may be pickled.Description of techniques, methods and equipment
In the brining and curing of meat products, the meat is treated with common salt (NaCl) and with one or more of the following curing salts: sodium nitrate (NaNO3), sodium nitrite (NaNO2), potassium nitrate (KNO3) or potassium nitrite (KNO2). The process is designed to produce an acceptable salt level in the product of about 1 – 3%, or a level of curing salt sufficient to produce an acceptable cured meat colour (which is produced by reaction of the meat pigment myoglobin with nitrite). Nitrite may be used per se or derived from nitrate, which is converted to nitrite in the curing system. The presence of salt and nitrite in the product inhibit microbial growth and enhance the durability and safety of the product. Thus salt and nitrite are essential to the curing process. Whereas the salt content is determined by consumer acceptability, the curing salt content is constrained by law. At present this is a maximum of 100 mg/kg of nitrite and 250 mg/kg of nitrate, as measured in the finished product. Other ingredients may be added to cured meats for a number of reasons, including taste. These include polyphosphates, sugars, spices, non-meat proteins and starches.Also certain types of cheese are brined for reasons of taste and preservation. Pickling of vegetables can be made by adding organic acids until the pH is below pH 4.3. In the process of making sauerkraut, salt is added (brining) to promote the growth of lactic acid bacteria, again for taste reasons and for conservation.