Per USDA regulations, sodium nitrate and sodium nitrite are not permitted in any kind of fresh pork sausage. On the other hand, cooked and cured meats like hams, hotdogs, pork smoked sausage, bologna and salami products contain sodium nitrite. USDA considers it a “restricted ingredient,” which means it is regulated and only allowed in very small amounts (in sodium nitrite’s case, 200 ppm ingoing). The process of cooking and smoking the cured meat actually uses up the ingoing nitrite: analysis of a finished product containing 200 ppm nitrite would typically have less than 10 ppm or less after the cooking process.
Many people think nitrites are bad for them. Actually, USDA has found the opposite: Based on available evidence to date, nitrite as used in meat and meat products is considered safe because known benefits outweigh potential risks. In summary, our fresh pork sausages do not contain sodium nitrite, but each of or fully cooked and cured items do. Nitrite in meat:
Adding nitrite to meat is only part of the curing process. Ordinary table salt (sodium chloride) is added because of its effect on flavor. Sugar is added to reduce the salt’s harshness. Spices and other flavorings are often added to achieve a characteristic “brand” flavor. Most—but not all—cured meat products are smoked after the curing process to impart a smoked meat flavor. Sodium nitrite, rather than sodium nitrate, is most commonly used for curing.
In a series of normal reactions, nitrite is converted to nitric oxide. Nitric oxide combines with myoglobin, the pigment responsible for the natural red color of uncured meat. They form nitric oxide myoglobin, which is a deep red color (as in uncooked dry sausage) that changes to the characteristic bright pink normally associated with cured and smoked meat (such as in wieners and ham) when heated during the smoking process.