spice and salt mixture containing nitrates or nitrites, which act to extend the shelf life of cured meats. Nitrates help remove excess moisture from the pork, decreasing water activity and limiting available free water for the growth of spoilage-causing and pathogenic microorganisms. Sodium nitrites are used to prevent the growth of botulism-causing bacteria and listeria monocytogenes, as well as imparting desirable flavour and colour. Nitrates are said to act like time-released nitrites and are used in pancetta products that require longer periods of curing and drying. Other constituents of the spice mixture also act to preserve the shelf life of pancetta—black pepper acts as an antibiotic, and sodium erythorbate is used as an antioxidant. Pancetta kept in its original packaging can be stored for up to 12 months. After opening, it has a shelf life of around 2–3 weeks in the refrigerator and up to 3 months in the freezer. Nutritional value One 30-g serving of pancetta contains around 5.0 g of protein, 11.0 g of fat, and 20–25 mg of cholesterol. One serving comprises between 15 and 22 percent of the accepted daily value of fats. Despite its high portion of daily fat value, pancetta has a lower fat content than other bacon products. A single serving of pancetta contains around 540 mg of sodium. Consumption of processed meats is reported to be the second largest source of dietary sodium consumption, with bacon products leading processed pork products in sodium content. Pancetta contains trace amounts of carbohydrates and no dietary fibre. These values can vary depending on processing, curing, and cooking methods. Health concerns Associated cancer risk is likely related to the presence of nitrosamines in processed meat products like pancetta. Nitrosamines are carcinogenic compounds formed by the reaction of nitrites and amines. Nitrites are added during processing to act as preservatives and as antibacterial agents against clostridium botulinum, the toxin that causes botulism. Amines are naturally-occurring compounds found in meats. Nitrosamines are often formed in high temperatures, like those required to produce bacon, one processed meat in which nitrosamines have been consistently found. Nitrosamines have also been shown to play a part in Alzheimer's and other neurodegenerative diseases, as well as type 1 and 2 diabetes. Regulations Under Canadian regulations (C.R.C., Annex C.2), a cured meat product like pancetta is an edible meat product prepared with salt with at least 100 ppm of sodium nitrate or potassium nitrate.