|technology > other processing techiques > brining, curing, ageing|
Brining, curing, pickling
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|
|Description of techniques, methods and equipment|
|Methods and equipment|
|c) Immersion brining/curing|
|d) Tumble/massage brining/curing|
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.
meat processing (e.g. bacon, ham). A prepared solution (i.e.brine) containing the ingredients is injected by needle(s) into the meat, either manually or by machine, to achieve a rapid deposition of curing salts and salt throughout the mass. After injection, the meat may be further processed or sealed in a plastic vacuum bag for a number of days, or immersed in a brine that will be identical or similar in composition to the injected brine.
water containing soluble product components are extracted from the product. The immersion brine may be discarded after each usage or it may be continually re-strengthened and re-used with only a bleed being discharged. Water extraction by brining can range from 5 -15% of the product weight. The salt content of the brine ranges from 5 - 20%.