The practice of adding substances to foods for easy storage is not a chemical or industrial invention, it is an ancient tradition. The use of salt was and still is a way to preserve meat and inhibit the growth of bacteria.
Examples of adding substances to food include: the addition of an acid juice (such as lemon) to prevent the blackening of a vegetable; the use of the smoke from wood especially ones rich in resin; and, in the specific case of the meat, the use of salt. The ancient Romans observed that saltpetre improved the production of cured meats and sausages, avoiding the browning of the meat and especially preventing the proliferation of unwanted bacteria.
Precisely for this reason, in the production of some cured meats, nitrates and nitrites are added in controlled quantities, as they have the property of maintaining the colour of meat.
In 2003, the European Food Safety Authority (EFSA) explicitly stated in a scientific opinion to the European Commission that “in most processed meat products the addition of nitrite (or nitrate) is necessary to prevent the development and production of toxins for C. botulinum”.
Thanks to the use of the refrigerator and microbiological knowledge, in addition to compliance with hygiene rules and to the exploitation of the bacteriostatic properties of spices and herbs such as garlic, pepper and chilli, you can nowadays produce safe cured meat using few preservatives.
In the PDO hams like Parma ham (PDO = Protected Designation of Origin), for example, the prolonged maturing process makes the use of nitrates unnecessary, which in fact are no longer used in these products. As for all substances, also in the case of these compounds an excess consumption can lead to negative consequences for health.
Although it should be noted that nitrates are a component of many plant foods (lettuce contains 3 grams per kg), the nutritional balance is the way to valorise the benefits of each individual food reducing health risks.
– EFSA: Re‐evaluation of potassium nitrite (E 249) and sodium nitrite (E 250) as food additives