Curing (food preservation)
Sea salt crystals crunch against the raw surface of a ham in 2024, beginning a chemical dance that has preserved food for millennia. This process relies on osmosis to draw moisture out of the meat and into the surrounding salt. When salt concentration reaches nearly 20 percent, it creates a solute-rich environment that is inhospitable to microbes. Water moves from areas of low solute concentration inside the microbe to the high concentration outside. The microbe shrivels and dies because it cannot survive without water. Salt also causes soluble proteins in sausage meat to rise to the surface during production. These proteins coagulate when heated, helping hold the sausage together. Without this specific chemical action, many cured meats would simply rot before they could be eaten.
A pink dye marks curing salt as distinct from ordinary table salt in modern kitchens. This color signals the presence of sodium nitrite or potassium nitrate mixed with sodium chloride. Nitrites bond to myoglobin in the meat, turning it red and inhibiting oxygen absorption. They also kill bacteria like Clostridium botulinum which cause botulism. However, these same chemicals generate known carcinogens such as nitrosamines when cooked at high temperatures. The World Health Organization classified processed meats as Group 1 carcinogens in 2015 after reviewing over 400 studies. Each daily serving of processed meat raises lifetime bowel cancer risk by 18 percent according to their data. The lethal dose for humans is about 22 milligrams per kilogram of body weight. Regulatory limits in the United States cap nitrite concentration at 200 parts per million. Some producers now use celery juice instead of added nitrates to bypass labeling restrictions while still introducing natural nitrates into the product.
Diodore of Sicily recorded that Cosséens people in Persia salted carnivorous animal flesh four centuries before Alexander the Great's campaign. Strabo noted that residents of Borsippa caught bats and salted them for consumption. Ancient Greeks prepared tarichos, a dish of meat and fish conserved by salt or other means. Romans called this dish something similar and later included salted fat and sauces within its definition. Polybius described how Gauls exported salt pork to Rome every year during his time between 200 and 118 BCE. These exports included rear cuts, middle cuts, hams, and sausages sold across the empire. Belgae herds provided skins and salt meat not just for Rome but for most of Italy. Ceretani of Spain drew large export income from succulent hams considered the most nourishing of all meats. In Ethiopia, Pliny wrote that Acridophages salted and smoked crickets arriving in swarms each spring as their sole food source. Salted meat became essential for feeding armies and populations during times of scarcity and famine.
Nicolas Appert developed air-tight storage methods in 1795 through experimentation that would become universal. The summer of 1857 in France was so hot that most butchers refused to slaughter animals due to inadequate conservation methods. A member of the Academy of Medicine and his son issued a 34-page summary proposing solutions to these problems. The 19th century saw the rise of canned salt meat like corned beef as part of the new food industry. The US Pure Food and Drug Act passed in 1906 following public demand for safer food. National agencies for health security emerged over the course of the 20th century to establish food traceability. Scientific research on lipolysis in vacuum-packed or frozen meat began in the 20th century regarding diet and human disease relationships. Scientists analyzed entrecôtes of frozen beef stored at specific temperatures for 270 days to study phospholipase effects. These studies found important enzymes accompanying the loss of unsaturated fats n-3 and n-6 already low in ruminant flesh.
New Zealand lamb could be sold as fresh meat rather than frozen after preservation techniques under controlled atmosphere appeared in the 1980s. This method allowed the meat to remain preserved from 12 to 16 weeks, sufficient duration to reach Europe by boat. Before this innovation, New Zealand meat had much lower value on European shelves because it was frozen. Chilled meats enabled New Zealand to compete more strongly with local producers of fresh meat globally. Controlled atmosphere use avoids depreciation affecting frozen meat in other markets including pork which now enjoys international trade. Improvement of transport means permitted separation of production areas from consumption areas without posing problems. Exportation of meats became possible even when distances were vast between regions. Salted Irish beef transported in barrels during the 18th century was considered finest among merchant marine and navy provisions. The ability to extend shelf life fundamentally changed how societies distributed food across continents.
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Common questions
How does salt preserve meat chemically?
Salt preserves meat by using osmosis to draw moisture out of the meat and into the surrounding salt. When salt concentration reaches nearly 20 percent, it creates a solute-rich environment that is inhospitable to microbes.
What health risks are associated with eating cured meats according to the World Health Organization?
The World Health Organization classified processed meats as Group 1 carcinogens in 2015 after reviewing over 400 studies. Each daily serving of processed meat raises lifetime bowel cancer risk by 18 percent according to their data.
When did ancient civilizations begin salting animal flesh for preservation?
Diodore of Sicily recorded that Cosséens people in Persia salted carnivorous animal flesh four centuries before Alexander the Great's campaign. Polybius described how Gauls exported salt pork to Rome every year during his time between 200 and 118 BCE.
Who developed air-tight storage methods for food preservation in 1795?
Nicolas Appert developed air-tight storage methods in 1795 through experimentation that would become universal. The summer of 1857 in France was so hot that most butchers refused to slaughter animals due to inadequate conservation methods.
How long can New Zealand lamb remain preserved using controlled atmosphere techniques from the 1980s?
This method allowed the meat to remain preserved from 12 to 16 weeks, sufficient duration to reach Europe by boat. Chilled meats enabled New Zealand to compete more strongly with local producers of fresh meat globally.