Safety Aspects of Nitrite and Nitrate in Cured Meats
It is essential to comply with the legal requirements for using additives such as sodium nitrite and sodium nitrate in the food industry. Nitrite and nitrate can be highly poisonous if they are used excessively. According to the data from “GRAS (Generally Recognized as Safe) Food Ingredients”, a single dose of 30 to 35 grams of potassium nitrate can be highly hazardous and possibly fatal to adult humans. The data also described that a single intake of sodium nitrate within the range of 22-23 mg/kg body weight can be deadly to human. Furthermore, research have found that inadequate consumption of potassium or sodium nitrate may cause methemoglobinemia (incapability of haemoglobin to convey oxygen) as a result of nitrate conversion to nitrite which can seriously compromise human health especially infants.
Studies have shown that the consumption of nitrite and nitrate may bring about endogenous development of Nnitroso substances. This is usually in response to the availability of nitrosatable precursors and depletion of substances like vitamin C. Ascorbic acid (vitamin C) as an inhibitor against the production of nitrosamines is legally required to be added (550 ppm in U.S.) in cured meats. Alternatively, application of erythorbic acid as an inhibitor is permitted in cured meats. Erythorbic acid contains less concentration of vitamin C but its functions (in discouraging nitrosamine development) are quite similar to ascorbic acid. Alpha-tocopherol (vitamin E) is also a beneficial antioxidant which is allowed to be used in certain types of cured meats to inhibit nitrosamine production.
If it is assumed that the application of nitrite and nitrate is implemented in an adequate way to the extent that every legal / moral obligation is met, it can be reasonable to claim that nitrite and nitrate present in cured meats are safe for human consumption. This is mainly due to the fact that only a small fraction of nitrite is sufficient to destroy target bacteria like Clostridium botulinum while enhancing the quality of meat to a satisfactory extent. In addition every cured meat is protected by the added antioxidants which are able to overcome potential formation of nitrosamine. The permitted amount of nitrite and nitrate (less than 200 ppm) is regulated / audited by some distinguished legal authorities such as FDA (Food and Drug Administration) and USDA (United States Department of Agriculture) in US or Food Standard Agency and Food Safety Act in UK.