In
food preparation, 'curing' refers to various
preservation and
flavoring processes, especially of
meat or
fish, by the addition of a combination of
salt,
sugar and either
nitrate or
nitrite. Many curing processes also involve
smoking. The etymology of the term is unclear, but it is thought to derive from the same Latin ''cura, -ae'', from which the other English meanings are also derived.
Terminology
Curing with salt and sugar may be called ''salting'', ''salt-curing'', ''sugar-curing'' or ''honey-curing''. The application of pellets of salt, called ''corns'', is often called ''corning''. Curing in a water solution or
brine is called ''wet-curing'' or ''
pickling'' or ''
brining''.
Paul Bertolli notes that a ''pickle'' contains nitrite in addition to salt. (Bertolli 2003) The curing of fish is sometimes called ''
kippering''.
Chemical action of curing
Salt inhibits the growth of spoilage-causing
microorganisms by drawing water out of microbial
cells through
osmosis. As the unwanted bacterial population decreases, other beneficial bacteria, primarily of the ''
Lactobacillus'' genus, come to the fore and generate an acidic environment (around 4.5
pH). The sugar included in the cure is used as food by the lactobacilli; generally
dextrose is preferred over
sucrose, or table sugar, because it seems to be more thoroughly consumed by the bacteria. This process is in fact a form of
fermentation, and, in addition to reducing further the ability of the spoilage bacteria to grow, accounts for the tangy flavor of some cured products. Concentrations of salt up to 20% are required to kill most species of unwanted bacteria.
Smoking adds chemicals to the surface of an item which affect the ability of bacteria to grow, inhibit oxidation (and thus rancidity), and improve flavor.
Nitrate and Nitrite Compounds
Nitrates and nitrites not only help kill bacteria, but also produce a characteristic flavor, and give meat a pink or red color. Nitrate (NO
3), in the form of either
sodium nitrate or
potassium nitrate, is used as a source for nitrite (NO
2). The nitrite further breaks down in the meat into
nitric oxide (NO), which then binds to the iron atom in the center of
myoglobin's heme group, preventing oxidation.
The presence of nitrates and nitrites in food is controversial due to the development of
nitrosamines when the food, primarily bacon, is cooked at high temperatures. The nitrate and nitrite compounds themselves are not harmful, however, and are among the
antioxidants found in fresh vegetables. (National Academy 1981) The usage of either compound is carefully regulated in the production of cured products; in the United States, their concentration in finished products is limited to 200 ppm, and is usually lower. Finally, they are irreplaceable in the prevention of
botulinum poisoning from consumption of dry-cured sausages.
History
Historically, peoples around the world have cured meat, in order not to waste valuable food, and to insure against poor harvests or hunting seasons. Although a salt-rich diet is currently implicated in risk for heart disease , in the past
protein deficiency was a greater problem.
Salt cod, which was air-dried in cool northern Europe, was a civilization-changing food product, in that a bountiful but perishable food supply could be converted to a form that allowed for wide travel and thus exploration.
Salted meat and fish are commonly eaten as a staple of the diet in
North Africa,
Southern China and in the
Arctic where they are associated with
nasopharyngeal cancer caused by infection by the
Epstein-Barr Virus. One study hypothesizes that the actual vector is
anaerobic bacteria found in salted fish. (The Scientist 1999)
Some cured food products
Cured animal products:
★
Anchovy
★
Prosciutto
★
Bresaola
★
Coppa
★
Salami
★
Lomo
★
Salt cod
★
Chorizo
★
Linguiça
★
Pepperoni
★
Capicola
★
Ham
★
Lardon
★
Bacon and
Pancetta
★
Lox (salmon)
★
Elenski but
Cured vegetable products:
★
Tofu
★
Sauerkraut
★
Kimchi
★
Pickled cucumbers
★
Pickled beets
★
Olives
See also
★
Curing salt
★
Food preservation
★
Smoking (food)
★
Sausage making
Notes and references
★ McGee, Harold. ''On Food and Cooking'' (revised). New York, NY: Scribner, 2004. ISBN 0-684-80001-2
★ Bertolli, Paul. ''Cooking by Hand''. New York, NY: Clarkson Potter/Publishers, 2003. ISBN 0-609-60893-2
★ National Academy of Sciences - National Research Council Academy of Life Sciences. "The Health Effects of Nitrate, Nitrite and N-Nitroso Compounds". Washington DC: National Academy Press, 1981.
★
Article in The Scientist, Volume 13, No. 6:1, Mar. 15, 1999 (registration required).
External links
★
National Center for Home Food Preservation - How do I...Cure & Smoke