A preservative is a substance that is added to products such as foods, pharmaceuticals, paints, biological samples, cosmetics, tires, wood, beverages, and many other products to prevent decomposition by microbial growth or by undesirable chemical changes. In general, preservation is implemented in two modes, chemical and physical. Chemical preservation entails adding chemical compounds to the product. Physical preservation entails processes such as refrigeration or drying. Preservative food additives reduce the risk of foodborne infections, decrease microbial spoilage, and preserve fresh attributes and nutritional quality. Some physical techniques for food preservation include dehydration, UV-C radiation, freeze-drying, and refrigeration. Chemical preservation and physical preservation techniques are sometimes combined.

Antimicrobial additives

Antimicrobial preservatives prevent degradation by bacteria. This method is the most traditional and ancient type of preserving—ancient methods such as pickling and adding honey prevent microorganism growth by modifying the pH level. The most commonly used antimicrobial preservative is lactic acid. Common antimicrobial preservatives are presented in the table.Nitrates and nitrites are also antimicrobial. The detailed mechanism of these chemical compounds range from inhibiting growth of the bacteria to the inhibition of specific enzymes.

Calcium propanoate or calcium propionate has the formula Ca(C₂H₅COO)₂. It is the calcium salt of propanoic acid.

Uses

As a food additive, it is listed as E number 282 in the Codex Alimentarius. Calcium propanoate is used as a preservative in a wide variety of products, including but not limited to: bread, other baked goods, processed meat, whey, and other dairy products. In agriculture, it is used, amongst other things, to prevent milk fever in cows and as a feed supplement Propanoates prevent microbes from producing the energy they need, like benzoates do. However, unlike benzoates, propanoates do not require an acidic environment.

Calcium propanoate is used in bakery products as a mold inhibitor, typically at 0.1-0.4% (though animal feed may contain up to 1%). Mold contamination is considered a serious problem amongst bakers, and conditions commonly found in baking present near-optimal conditions for mold growth.

A few decades ago, Bacillus mesentericus (rope), was a serious problem, but today's improved sanitary practices in the bakery, combined with rapid turnover of the finished product, have virtually eliminated this form of spoilage. Calcium propanoate and sodium propanoate are effective against both B. mesentericus rope and mold.

Sodium propanoate or sodium propionate is the sodium salt of propionic acid which has the chemical formula Na(C₂H₅COO). This white crystalline solid is deliquescent in moist air.

Reactions

It is produced by the reaction of propionic acid and sodium carbonate or sodium hydroxide.

Uses

It is used as a food preservative and is represented by the food labeling E number E281 in Europe; it is used primarily as a mold inhibitor in bakery products. It is approved for use as a food additive in the EU, USA and Australia and New Zealand (where it is listed by its INS number 281).

See Also

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