Many chemicals will kill micro-organisms or stop their growth but most of these are not permitted
in foods; chemicals that are permitted as food preservatives are listed in the next table.
The preservation of products containing chemical food preservatives is usually based on the
combined or synergistic activity of several additives.
Intrinsic product parameters (e.g composition, acidity, water
activity)
Combinations of additives and preservatives systems provide unlimited preservation alternatives for applications in food products
to meet consumer demands for healthy and safe food
Chemical food preservatives are applied to foods:
As direct additives during processing
Develop by themselves during processes such as fermentation
Certain preservatives have been used either accidentally or intentionally for centuries and include
sodium chloride , sugar,acids, alcohols and components of smoke.
Traditional chemical food preservatives and their use in fruit and vegetable processing technologies
could be summarised as follows:
C. Foods preserved by high sugar concentrations: jellies, preserves, syurps,
juice concentrates.
A. Common salt: brined vegetables.
B. Sugars(sucrose, glucose, fructose and syups)
D. Interaction of sugar with other ingredients of processes such as
drying and heating
E. Indirect food preservation by sugar in products where fermentation is
important (naturally acidified pickles and sauerkraut)
extrinsic factors (e.g processing temperature, storage atmosphere and
temperature)