LPT 321: Meat Science (1+1)

Salting and Pickling

SALTING

• Salting, a very ancient method of preservation is the process of applying dry salt on the surface of meat and rubbing it to extend the shelf life of meat.
• In salted meat, dry salt is applied to the meat which dissolves in the meat fluid near the surface and further withdraws fluid from the meat forming a hypertonic solution.
• It then passes slowly inward, dissolves throughout the meat substance  , until the concentration of salt is approximately the same throughout the meat substance
• Thus salt has no harmful effects on the bacteria but act by extraction of water from the meat, by exerting a strong osmotic pressure, causing a drying effect and rendering water non-available to bacteria.
• Higher concentration of salt gives greater preservative action. The principle involved in applying salt is dehydration and germicidal.
• Most of non-marine bacteria can be inhibited by 20% or less sodium chloride, while some moulds generally tolerate higher levels.
• Organisms that can grow in the presence of and require high concentrations of salt be termed as halophiles, while, those that can withstand but not grow in higher concentration are termed as halodurics.
• In curing halophiles are allowed to grow and halodurics are kept at low levels.
• The difference in the growth rate of these two kinds of bacteria is taken advantage of in the curing of meats.
• Salted meat is different from cured meat (Example-Ham, Bacon, Corned beef, etc.,). In curing, sugar and other salts such as sodiun nitrate/nitrite are added either as a dry cure or as brine solution.
• Parasitic cysts, cysticerci, in meat are fairly rapidly destroyed, when the ratio of the salt to moisture in the meat is not more than 1:4. At that concentration the cysticerci are viable after 16 hours but 50% are destroyed after 90 hours and all are rendered non-viable after 136 hours.
• The destruction of parasitic cysts in biltong may therefore be ensured by submitting the biltong to an adequate salt concentration followed by a holding period of not less than 6 days.