Page 25 - Curriculum Visions Dynamic Book

Preserving
In general, the food that we eat is harvested at one time of the year and eaten over the subsequent weeks and months. In the past, when people did not have freezers, they had to use chemical means to preserve food. One way was to use salt.
Salt preserves food by binding itself to the water in food so that micro-organisms cannot use it. It also sucks water out of the bacteria, killing them.
There are a number of ways that food can be preserved by salt. Fish and some meats are packed in salt, and have salt rubbed into their skins.
Curing is a process of adding salt to meat.
It is the same as pickling. Bacon is the most common cured meat, produced by salting pork bellies, ham and shoulder.
The salt is first rubbed into the meat and then brine is injected into the meat using a tool with many needles. This gets the brine inside the meat in an even manner. It is then sometimes hung in wood smoke for a number of days.
Pickling is a way of preserving food
using salt and water – brine. It suits some vegetables and meats better than others. Common foods that have been pickled in brine include sauerkraut (pickled cabbage), and gherkins (pickled cucumbers).
Other foods that can be pickled include sardines, mackerel and eggs.
Not only does the salt prevent decay, it also sucks the moisture from the food, drying it out, although this is different from the process called dehydration. This is why many salted foods have to be soaked in water for long periods in order to get the excess salt out before they can be eaten and to make the food moist enough for it to be chewed.
Also...
The principle at work in taking the water out of material by packing or pickling them in salt is osmosis. This causes water to move through a semipermeable membrane (filter) such as skin if the concentration of salt on one side of the membrane is greater than on the other side. Pickling materials in a brine solution means that the brine has a more concentrated solution than the food, hence water moves from the food into the brine.
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dissolve: to break down a substance in a solution without a resultant reaction.
freezing point: the temperature at which a substance changes from a liquid to a solid. It is the same temperature as the melting point.
osmosis: a process where molecules of a liquid solvent move through a membrane (filter) from a region of low concentration to a region of high concentration of solute.