Food Preservation Methods & Common Preservatives
Preservatives
Food spoilage is caused by bacteria, yeast, and mold, leading to economic losses for manufacturers, distributors, and consumers. Some microorganisms produce harmful toxins, such as botulinum toxin (found in improperly sterilized canned goods) and aflatoxins (produced by certain molds), which are highly toxic and carcinogenic.
Methods of Food Preservation
There are two main approaches to preventing food spoilage:
- Physical methods: These include irradiation, heating, dehydration, and freezing to kill or inhibit the growth of microorganisms.
- Chemical methods: These involve using preservatives that eliminate or prevent the growth of microorganisms.
Common Preservatives
Formats (E-236 to E-238)
Formic acid and its derivatives are not authorized for use as food preservatives in Europe, the United States, and many other countries.
Acetates (E-260 to E-263)
Acetic acid and its salts, such as calcium acetate, are commonly used in escabeche, brines, and pickles. They are considered harmless.
Propionates (E-280 to E-283)
Propionic acid and its salts are highly effective against mold growth. They are widely used in bread production and some bakery products. They are also used to prevent mold growth on certain cheeses, such as Emmentaler.
Sorbates (E-200 to E-203)
Sorbic acid and its salts are used in a wide variety of food products, including soft drinks, pastries, meat products, cheeses, olives, canned fruit, dairy desserts, butter, margarine, and jam. They are also used in winemaking to reduce sulfite levels. Sorbates are authorized for use worldwide.
Benzoates (E-210 to E-213)
Benzoic acid and its salts are used in flavored soft drinks, jams, emulsified sauces, and quince. They have a cumulative effect but are not considered mutagenic or carcinogenic by the World Health Organization. The acceptable daily intake is up to 5 mg per kg of body weight.
Parahydroxybenzoates (Parabens) (E-214 to E-216)
Parabens are effective against molds and yeasts, and to a lesser extent, bacteria. They are active in neutral environments, unlike other preservatives that require acidic conditions. Parabens are considered less toxic than benzoic acid.
Polychlorinated Biphenyls (PCBs) (E-230 to E-232)
PCBs are highly toxic substances and are only permitted for surface treatment of citrus fruits and in some food wraps.
Hexamethylenetetramine (E-239)
Hexamethylenetetramine is used as a preservative in pickles and canned crab or shrimp. The European Union only permits its use to prevent swelling in Provolone cheese, with a maximum residual amount of 25 mg/kg (expressed as formaldehyde).
Formaldehyde (E-240)
Formaldehyde is not authorized as a food additive in the EU and most other countries due to its weak carcinogenic and mutagenic properties. However, it is used for industrial equipment disinfection.
Dimethyl Pyrocarbonate (E-242)
Dimethyl pyrocarbonate is used for cold disinfection of flavored drinks, tea, alcoholic beverages, and concentrated wines. While it is toxic in its concentrated form, it is not present in the final food product. The European Union’s Scientific Committee for Food has recently approved its use in wines with alcohol.
Carbon Dioxide (E-290)
Carbon dioxide is used in controlled atmosphere packaging for cheese and meat, as well as in the production of carbonated soft drinks. It is harmless.
Boric Acid and Sodium Tetraborate (E-285 and E-284)
In Europe, boric acid and sodium tetraborate are only permitted in caviar. Chronic use can lead to borism, characterized by dry skin, rashes, and gastric upsets. Their use is banned worldwide except for preserving caviar.
Chlorine (Cl2) (E-925)
Chlorine is used as a disinfectant for water and equipment in the food industry, as well as for treating drinking water and flour. It is essential for ensuring the hygienic quality of drinking water.
Lysozyme (E-1105)
Lysozyme, derived from fish and shellfish, has potential as a food additive and has garnered interest in countries like Japan. The EU approves its use in ripened cheeses without limitations. It is considered harmless.
Antibiotics
With the exception of nisin and natamycin, all other antibiotics are reserved for medical use in the European Union. Their use as food preservatives is prohibited to prevent the emergence of resistant bacterial strains and potential disruption of consumers’ intestinal flora. The use of antibiotics in veterinary medicine is also regulated to prevent them from reaching consumers through meat or milk.
- Nisin (E-234): Permitted in semolina, tapioca, processed cheese, matured cheese, clotted cream, and mascarpone.
- Natamycin (Pimaricin) (E-235): Allowed for surface treatment of hard or semi-hard cheeses and cured meats.
Hydrogen Peroxide
The use of hydrogen peroxide as a food preservative is prohibited.