Curing salt

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Curing salt

Curing salt is used in meat processing to generate a pinkish shade and to extend shelf life.[1] It is both a color agent and a means to facilitate food preservation as it prevents or slows spoilage by bacteria or fungus. Curing salts are generally a mixture of sodium chloride (table salt) and sodium nitrite, and are used for pickling meats as part of the process to make sausage or cured meat such as ham, bacon, pastrami, corned beef, etc. Though it has been suggested that the reason for using nitrite-curing salt is to prevent botulism, a 2018 study by the British Meat Producers Association determined that legally permitted levels of nitrite have no effect on the growth of the Clostridium botulinum bacteria that causes botulism, in line with the UK’s Advisory Committee on the Microbiological Safety of Food opinion that nitrites are not required to prevent C. botulinum growth and extend shelf life.[2] (see also Sodium Nitrite: Inhibition of microbial growth).

Many curing salts also contain red dye that makes them pink to prevent them from being confused with common table salt.[3] Thus curing salt is sometimes referred to as "pink salt". Curing salts are not to be confused with Himalayan pink salt, a halite which is 97–99% sodium chloride (table salt) with trace elements that give it a pink color.

Types[edit]

There are many types of curing salts often specific to a country or region.

Prague Powder #1[edit]

One of the most common curing salts. It is also called Insta Cure #1 or Pink curing salt #1. It contains 6.25% sodium nitrite and 93.75% table salt.[4] It is recommended for meats that require short cures and will be cooked and eaten relatively quickly. Sodium nitrite provides the characteristic flavor and color associated with curing.

Prague Powder #2[edit]

Also called Pink curing salt #2. It contains 6.25% sodium nitrite, 4% sodium nitrate, and 89.75% table salt.[4] The sodium nitrate found in Prague powder #2 gradually breaks down over time into sodium nitrite, and by that time a dry cured sausage is ready to be eaten, no sodium nitrate should be left.[3] For this reason it is recommended for meats that require long (weeks to months) cures, like hard salami and country ham.

Saltpetre[edit]

Another name for potassium nitrate (KNO3), saltpetre, also called saltpeter or nitrate of potash, has been a common ingredient of some types of salted meat for centuries[5] but its use has been mostly discontinued due to inconsistent results compared to nitrite compounds (KNO2, NaNO2, NNaNO2, etc.) Even so, saltpetre is still used in some food applications, such as some charcuterie products. It should not be confused with Chile saltpetre or Peru saltpetre, which is sodium nitrate (NaNO3).

Cancer[edit]

Carcinogenicity is the ability or tendency of a chemical to induce tumors, increase their incidence or malignancy, or shorten the time of tumor occurrence.[6]

Adding nitrite and nitrate to meat has been shown to generate known carcinogens such as nitrosamines; the World Health Organization (WHO) advises that each 50 g (1.8 oz) of "processed meats" eaten a day would raise the risk of getting bowel cancer by 18% over a lifetime; "processed meat" refers to meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavour or improve preservation. The World Health Organization's review of more than 400 studies concluded, in 2015, that there was sufficient evidence that "processed meats" caused cancer, particularly colon cancer; the WHO's International Agency for Research on Cancer (IARC) classified "processed meats" as carcinogenic to humans (Group 1); "processed meat" meaning meat that has been transformed through salting, curing, fermentation, smoking, or other processes to enhance flavour or improve preservation.[7]

Nitroso-compounds can be formed during the curing process used to preserve meats, or when nitrate-treated or nitrite-treated meat is cooked, and also from the reaction of nitrite with secondary amines under acidic conditions (such as occurs in the human stomach). Dietary sources of nitrosamines include US cured meats preserved with sodium nitrite as well as the dried salted fish eaten in Japan. In the 1920s, a significant change in US meat curing practices resulted in a 69% decrease in average nitrite content. This event preceded the beginning of a dramatic decline in gastric cancer mortality.[8] Around 1970, it was found that ascorbic acid (vitamin C), an antioxidant, inhibits nitrosamine formation.[9] Consequently, the addition of at least 550 ppm of ascorbic acid is required in meats manufactured in the United States. Manufacturers sometimes instead use erythorbic acid, a cheaper but equally effective isomer of ascorbic acid. Additionally, manufacturers may include α-tocopherol (vitamin E) to further inhibit nitrosamine production. α-Tocopherol, ascorbic acid, and erythorbic acid all inhibit nitrosamine production by their oxidation-reduction properties. Ascorbic acid, for example, forms dehydroascorbic acid when oxidized, which when in the presence of nitrosonium, a potent nitrosating agent formed from sodium nitrite, reduces the nitrosonium into nitric oxide.[10] The nitrosonium ion formed in acidic nitrite solutions is commonly[11][12] mislabeled nitrous anhydride, an unstable nitrogen oxide that cannot exist in vitro.[13]

Nitrate or nitrite (ingested) under conditions that result in endogenous nitrosation has been classified as "probably carcinogenic to humans" by IARC.[14][15] The World Health Organization's review of more than 400 studies concluded, in 2015, that there was that there was sufficient evidence that "processed meats" caused cancer, particularly colon cancer.[16]

Further reading[edit]

  • Coudray, Guillaume. Who poisoned your bacon? The dangerous history of meat additives. London: Icon Books, 2021. [1]

See also[edit]

  • Curing (food preservation) – Food preservation and flavoring processes based on drawing moisture out of the food by osmosis
  • Brining – Food processing by treating with brine or salt
  • Bacon – Type of salt-cured pork
  • Charcuterie – Branch of cooking of prepared meat products, primarily from pork
  • Cured fish
  • List of dried foods – Wikipedia list article
  • Salt – Mineral used as ingredient, composed primarily of sodium chloride
  • Sausage making – Sausage production processes
  • Biltong – Form of dried, cured meat that originated in South Africa

References[edit]

  1. ^ Sárraga, C.; Gil, M.; Arnau, J.; Monfort, J. M.; Cussó, R. (1989). "Effect of curing salt and phosphate on the activity of porcine muscle proteases". Meat Science. Elsevier Science. 25 (4): 241–249. doi:10.1016/0309-1740(89)90042-9. PMID 22054673.
  2. ^ Doward, Jamie (2019-03-23). "Revealed: no need to add cancer-risk nitrites to ham". The Observer. London. Archived from the original on 2021-01-26. Retrieved 2021-02-14. The results show that there is no change in levels of inoculated C botulinum over the curing process, which implies that the action of nitrite during curing is not toxic to C botulinum spores at levels of 150ppm [parts per million] ingoing nitrite and below.
  3. ^ a b Bitterman, M. (2010). "Salt Reference Guide". Salted: A Manifesto on the World's Most Essential Mineral, with Recipes. Random House. p. 187. ISBN 978-1580082624. Retrieved 2013-08-16.
  4. ^ a b Gisslen, W. (2006). "Sausages and Cured Foods". Professional Cooking, College Version. Hoboken, New Jersey: John Wiley & Sons. p. 827. ISBN 9780471663744. Retrieved 2013-08-16.
  5. ^ Lauer, Klaus (1991). "The history of nitrite in human nutrition: A contribution from German cookery books". Journal of Clinical Epidemiology. 44 (3): 261–264. doi:10.1016/0895-4356(91)90037-a. ISSN 0895-4356. PMID 1999685.
  6. ^ "Known and Probable Human Carcinogens". www.cancer.org. Retrieved 28 January 2019.
  7. ^ "IARC Monographs evaluate consumption of red meat and processed meat" (PDF). International Agency for Research on Cancer. 2015-10-26. Archived from the original (PDF) on 2021-01-18. Retrieved 2021-02-14. Processed meat was classified as carcinogenic to humans (Group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer.
  8. ^ Paik, David C; Saborio, David V; Oropeza, Ruben; Freeman, Harold P (February 2001). "The epidemiological enigma of gastric cancer rates in the US: was grandmother's sausage the cause?". International Journal of Epidemiology. 30 (1): 181–182. doi:10.1093/ije/30.1.181. PMID 11171883.
  9. ^ Mackerness, C.W.; Leach, S.A.; Thompson, M.H.; Hill, M.J. (1989). "The inhibition of bacterially mediated N -nitrosation by vitamin C: relevance to the inhibition of endogenous N -nitrosation in the achlorhydric stomach". Carcinogenesis. 10 (2): 397–399. doi:10.1093/carcin/10.2.397. PMID 2492212.
  10. ^ "Research Newsletter". Linus Pauling Institute. 1 July 2014. Retrieved 1 April 2018.
  11. ^ Scanlan, RA (May 1983). "Formation and occurrence of nitrosamines in food". Cancer Research. 43 (5 Suppl): 2435s–2440s. PMID 6831466. NAID 80001710206.
  12. ^ Nollet, Toldra, D (2015). Handbook of Food Analysis (Third ed.). p. 290. ISBN 978-1-4822-9784-3.[page needed]
  13. ^ Williams, D.L.H. (2004). "Reagents effecting nitrosation". Nitrosation Reactions and the Chemistry of Nitric Oxide. pp. 1–34. doi:10.1016/B978-044451721-0/50002-5. ISBN 978-0-444-51721-0.
  14. ^ "List of classifications, Volumes 1–116 – IARC Monographs on the Evaluation of Carcinogenic Risks to Humans". International Agency for Research on Cancer (IARC) – World Health Organization (WHO). 2010. Retrieved 25 September 2016.
  15. ^ VOLUME 94 – Ingested Nitrate and Nitrite, and Cyanobacterial Peptide Toxins – IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. International Agency for Research on Cancer (IARC) – World Health Organization (WHO). 2010. ISBN 978-92-832-1294-2. Retrieved 25 September 2016.
  16. ^ "IARC Monographs evaluate consumption of red meat and processed meat" (PDF). International Agency for Research on Cancer. 2015-10-26. Archived from the original (PDF) on 2021-01-18. Retrieved 2021-02-14. Processed meat was classified as carcinogenic to humans (Group 1), based on sufficient evidence in humans that the consumption of processed meat causes colorectal cancer.