Ham

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Typical slice of ham
Whole ham

Ham is a processed pork foodstuff,1 which undergoes preservation through curing, smoking, or salting. Ham was traditionally made only from the hind leg of swine, and referred to that specific cut of pork.2 Ham is made around the world, including a number of regional specialties, although the term now has wider usage and can also be used to refer to meat which has been through a process of re-forming.

The precise nature of meat termed "ham" is controlled, often by statute, in a number of areas, including the United States and European Union, meaning that only products meeting a certain set of criteria can be called ham. In addition, there are numerous ham products which have specific geographical naming protection, such as Prosciutto di Parma in Europe, and Smithfield ham in the US.

Ham is also often colloquially used to mean any sliced (or re-formed) preserved meat, regardless of the animal it is made from, although this is usually qualified with the species of animal as with turkey ham.

Definition

Ham has a number of definitions, and its meaning has evolved over time. Ham was originally the cut of pork deriving from the hind legs of swine, which was then often preserved through processes such as curing, smoking, or salting. Cooked leg of pork is called gammon.

Because of the preservation process, ham is a compound foodstuff or ingredient, being made up of the original meat, as well as the remnants of the preserving agent(s), such as salt, but it is still recognised as a food in its own right.3

In many countries the term is now protected by statute, with a specific definition. For instance, in the United States, the Code of Federal Regulations (CFR) says that "the word 'ham', without any prefix indicating the species of animal from which derived, shall be used in labeling only in connection with the hind legs of swine".4

In addition to the main categories, some processing choices can affect legal labeling. For instance, in the United States, a "smoked" ham must have been smoked by hanging over burning wood chips in a smokehouse or an atomized spray of liquid smoke such that the product appearance is equivalent; a "hickory-smoked" ham must have been smoked using only hickory. However, injecting "smoke flavor" is not legal grounds for claiming the ham was "smoked"; these are labeled "smoke flavor added". Hams can only be labelled "honey-cured" if honey was at least 50% of the sweetener used, is at least 3% of the formula, and has a discernible effect on flavor. So-called "lean" and "extra lean" hams must adhere to maximum levels of fat and cholesterol per 100 grams of product.

Ham re-formed from smaller pieces in to a larger block also has to be labelled in many jurisdictions.

Etymology

The word "ham" is derived from the Old English ham or hom meaning the hollow or bend of the knee, from a Germanic base where it meant "crooked". It gained the meaning of the leg of an animal around the 15th century.5

History

The preserving of pork leg as ham has a long history, with Cato the Elder writing about the "salting of hams" in his De Agri Cultura tome around 160 BC.6

There are claims that the Chinese were the first people to mention the production of raw cured ham,7 whilst Larousse Gastronomique claims an origin from Gaul,8 but it was certainly well established by the Roman period, including an import trade from Gaul mentioned by Marcus Terentius Varro in his writings.7

Method

There are several methods for producing ham from raw meat, and this is undertaken to preserve and flavour the meat. Most ham is safe to eat following preservation, without the need for cooking.

Dry curing

Traditional dry cure hams may use only salt as the curative agent, such as with San Daniele or Parma hams, although this is comparatively rare.9 This process involves cleaning the raw meat, covering it in salt (for about two months for Parma ham) while it is gradually pressed – draining all the blood. It is then washed and hung in a dark, temperature-regulated place until dry. It is then hung to air for another period of time.

Sea salt being added to raw pork leg as part of a dry cure process

The duration of the curing process varies by the type of ham, with Serrano ham curing in 9–12 months, Parma hams taking more than 12 months, and Iberian ham taking up to 2 years to reach the desired flavour characteristics.10 Dry cured hams, such as the Chinese Jinhua ham takes approximately 8 to 10 months to complete.11

Most modern dry cure hams also use nitrites (either sodium or potassium), which are added along with the salt, although following a similar methodology. The nitrites deliver a distinctive pink or red tinge to the meat, as well as imparting flavour. The amount and mixture of salt and nitrites used has an effect on the shrinkage of the meat.12

Sodium nitrite is used because it prevents bacterial growth and, in a reaction with the meat's myoglobin, gives the product a desirable dark red color. Because of the toxicity of nitrite (the lethal dose of nitrite for humans is about 22 mg per kg body weight), some areas specify a maximum allowable content of nitrite in the final product. Under certain conditions, especially during cooking, nitrites in meat can react with degradation products of amino acids, forming nitrosamines, which are known carcinogens.13

The dry curing of ham involves a number of enzymatic reactions. The enzymes involved are proteinases (cathepsinsB, D, H & L, and calpains) and exopeptidases (peptidase and aminopeptidase).14 These enzymes cause proteolysis of muscle tissue, which creates large numbers of small peptides and free amino acids, while the adipose tissue undergoes lipolysis to create free fatty acids.14 Salt and phosphates act as strong inhibitors of proteolytic activity.15

Animal factors influencing enzymatic activity include age, weight, and breed.16 During the process itself, conditions such as temperature, duration, water content, redox potential, and salt content all have an effect.14

The salt content in dry-cured ham varies throughout a piece of meat, with gradients determinable through sampling and testing or non-invasively through CT scanning.17

Wet curing

Wet curing involves the immersion of the meat in a brine, sometimes with other ingredients such as sugar also added for flavour. Meat is submerged in the brine for around 3–14 days, during which time the meat needs to be kept submerged, and the brine mixture agitated periodically to prevent separation of the ingredients.9

Wet curing also has the effect of increasing volume and weight of the finished product, by about 4%.

The wet curing process can also be replicated by using mechanical pumping using needles and curing solution. This can be quicker, increase the weight of the finished product by more than immersion wet curing, and ensure a more even distribution of salt through the meat. This process is quicker than traditional wet cure, normally being completed between a few days and a few weeks.18

Smoking

Ham can also be preserved through the smoking method, in which the meat is placed in a smokehouse (or equivalent) to be cured by the action of smoke.

The main flavor compounds of smoked ham are guaiacol, and its 4-, 5-, and 6-methyl derivatives as well as 2,6-dimethylphenol. These compounds are produced by thermal breakdown (i.e., combustion) of lignin, a major constituent of wood used in the smokehouse.19

Protected designations

Hams aging in an atmospherically controlled storage room in Mazerolles, Béarn
Spanish Jamón de Guijuelo, a protected designation ham

There are a wide number of hams worldwide which have some level of protection of their unique characteristics, usually relating to their method of preservation and/or location of production or processing. Dependent on jurisdiction, rules may prevent any other product being sold with the particular appellation, such as through the European protected geographical indication.

Uses

A pizza with buffalo mozzarella and cooked ham

Ham is typically used in its sliced form, often as a filling for sandwiches and similar foods, such as in the ham sandwich and ham and cheese sandwich. Other variations include toasted sandwiches such as the croque-monsieur.

It is also used chopped in a wide range of dishes, such as omelettes.

Preserved ham can be cooked (although there is no requirement), and usually requires washing in water to remove salt. Whole fresh pork leg is also served cooked as gammon, known as ham in the United States.

Health effects

As a processed meat, there has been concern over the health effects of ham consumption.26 A meta-analysis study has shown a statistically relevant correlation between processed meat consumption and the risk of pancreatic cancer, with an increase in consumption of 50 grams (1.8 oz) per day leading to a 19% increase in risk.27

This supported earlier studies, including the 2007 study Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective, by the World Cancer Research Fund and the American Institute for Cancer Research,28 which reviewed more than 7,000 studies published worldwide.29 Among the recommendations was that, except for very rare occasions, people should avoid eating ham or other processed meats – cured, smoked, salted or chemically preserved meat products such as bacon, hot dogs, sausage,30 salami,31 and pastrami. The report states that once an individual reaches the 510 grams (18 oz) weekly limit for red meat, every 48 grams (1.7 oz) of processed meat consumed a day increases cancer risk by 21%.29

A European cohort study also positively correlated processed meat consumption with higher all-cause mortality, with an estimation that 3.3% of deaths in the cohort could have been prevented by consuming less than 20 grams (0.71 oz) of processed meat per day.32

Hams in art

See also

References

  1. ^ "Red and processed meats and cancer prevention". World Cancer Research Fund. 
  2. ^ "Bacon: Bacon and Ham Curing" in Chambers's Encyclopædia. London: George Newnes, 1961, Vol. 2, p. 39.
  3. ^ "Labelling and Composition of Meat Products: Guidance Notes". Food Standards Agency Scotland. p. 31. 
  4. ^ "9 CFR 317.8 - False or misleading labeling or practices generally; specific prohibitions and requirements for labels and containers". Legal Information Institute. 
  5. ^ Brown, Lesley, ed. (2007). Shorter Oxford English Dictionary II (Sixth ed.). Oxford: Oxford University press. p. 3611. 
  6. ^ Callow, EH (December 1947). "The Action of Salts and other Substances Used in the Curing of Bacon and Ham". British Journal of Nutrition 1 (2-3): 269–274. doi:10.1079/bjn19470037. 
  7. ^ a b Zeuthen, Peter. Meat Fermentation Worldwide: History and Principles. 
  8. ^ Larousse Gastronomique. Hamlyn. 2009. ISBN 978-0-600-62042-6. 
  9. ^ a b "Curing Methods". Meat and Sausages.com. 
  10. ^ Sentandreu, Miguel Angel; Toldrá, Fidel (2001). "Dipeptidyl peptidase activities along the processing of Serrano dry-cured ham". European Food Research and Technology 213 (2): 83–87. doi:10.1007/s002170100355. 
  11. ^ Zhou, G.H.; Zhao, G.M. (2007), "Biochemical changes during processing of traditional Jinhua ham", Meat Science (77): 114–120 
  12. ^ Wierbicki, Eugen; Howker, John J (1976). "Effect of salt, phosphates and other curing ingredients on shrinkage of lean pork meat and quality of smoked processed ham". Journal of Food Science 41 (5): 1116–1121. doi:10.1111/j.1365-2621.1976.tb14399.x. 
  13. ^ Jakszyn, P.; Gonzalez, C. A. (2006). "Nitrosamine and related food intake and gastric and oesophageal cancer risk: A systematic review of the epidemiological evidence". World journal of gastroenterology : WJG 12 (27): 4296–4303. PMID 16865769.  
  14. ^ a b c Toldrá, Fidel; Flores, Mónica (1998). "The Role of Muscle Proteases and Lipases in Flavor Development During the Processing of Dry-Cured Ham". Critical Reviews in Food SCience and Nutrition 38 (4): 351–352. doi:10.1080/10408699891274237. 
  15. ^ Sárraga, Carmen; Gil, Marta; Arnau, Jacint; Monfort, Josep M (1989). "Effect of curing salt and phosphate on the activity of porcine muscle proteases". Meat Science 24 (4): 241–249. doi:10.1016/0309-1740(89)90042-9. 
  16. ^ Sárraga, Carmen; Gil, Marta; García-Regueiro, José Antonio (Sep 2006). "Comparison of calpain and cathepsin (B,L and D) activities during dry-cured ham processing from heavy and large white pigs". Journal of the Science of Food and Agriculture 62 (1): 71–75. 
  17. ^ Vestergaard, Christian; Erbou, Søren G; Thauland, Torunn; Adler-Nissen, Jens; Berg, Per (January 2005). "Salt distribution in dry-cured ham measured by computed tomography and image analysis". Meat Science 69 (1): 9–15. doi:10.1016/j.meatsci.2004.06.002. 
  18. ^ Deibel, RH; Niven, CF (September 1958). "The occurrence and significance of a motile microorganism of the Genus Lactobacillus in ham curing brines". Applied Microbiology 5 (5): 323–327. PMC 1057423. 
  19. ^ Wittkowski, Reiner; Ruther, Joachim; Drinda, Heike; Rafiei-Taghanaki, Foroozan "Formation of smoke flavor compounds by thermal lignin degradation" ACS Symposium Series (Flavor Precursors), 1992, volume 490, pp 232–243. ISBN 9780841222229
  20. ^ http://www.delo.si/novice/slovenija/zdaj-uradno-originalen-kraski-prsut-zasciten-v-eu.html
  21. ^ Regulator Agency of the Serrano Ham D.O., Jamón de Teruel.com
  22. ^ "Campaña informativa sobre los Productos del Ibérico del Ministerio de Agricultura de España". Web.archive.org. 2008-05-22. Archived from the original on 2008-05-22. Retrieved 2013-09-08. 
  23. ^ A colour atlas of food quality control, section "Brine curing", pages 65 and 66. Jane P. Sutherland, A. H. Varnam
  24. ^ "Food Legends of the United Kingdom: York Ham". Information Britain. Retrieved 11 November 2009. 
  25. ^ Lori Alden. "Cook's Thesaurus: Ham". Food Subs. Retrieved 5 October 2008. 
  26. ^ Gallagher, James. "Processed meat 'early death' link". BBC News. 
  27. ^ Larsson, SC; Wolk, A (2012). "Red and processed meat consumption and risk of pancreatic cancer: meta-analysis of prospective studies". British Journal of Cancer 106 (3): 603–607. doi:10.1038/bjc.2011.585. 
  28. ^ "Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective". The World Cancer Research Fund and the American Institute for Cancer Research. 2007-10-31. Retrieved 2009-09-18. 
  29. ^ a b Tina Marie Macias (2007-10-31). "Body fat is linked to six types of cancers". Los Angeles Times. Retrieved 2009-09-18. 
  30. ^ "Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective". The World Cancer Research Fund and the American Institute for Cancer Research. 2007-10-31. p. 117. Retrieved 2009-09-18. 
  31. ^ "Be thin to cut cancer, study says". BBC News. 2007-10-31. Retrieved 2009-09-18. 
  32. ^ Rohrmann et al. (7 March 2013). "Meat consumption and mortality - results from the European Prospective Investigation into Cancer and Nutrition". BMC Medicine 11 (63). 

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