Salt is used to preserve , pork and fish. The food is soaked in brine or it is rubbed with dry salt. Any micro organism on such food will be killed as the high salt solution will remove water from its cells by osmosis.
Sugar is canned to make jams and jellies from fruits. Syrup is added to canned fruits. Generally sugar improves the flavour of the food. Sugar also has the same effect on micro organisms as salt.
Vinegar is used to pickle vegetables, meat and fish. As it is an acid, it gives a sour taste to preserve food. Growth of micro organisms is slowed down by the acidic medium of the food.
F. Fish and meat can be preserved by smoking. Often, this process is combined with salting and drying. This is known as curing. Ham and bacon are prepared on this way.
Other important chemical preservatives include sodium benzoate, nitrites and sulphites. Only chemicals approved by law can be used as food preservatives.
