Nitric acid sodium salt
Sodium nitrate has been used for centuries to cure meat.
Bacterial action during curing converts the sodium nitrate into sodium nitrite, which kills the bacteria that cause botulism, and combines with the myoglobin in the meat to form the pink color associated with ham.
These days, sodium nitrite replaces most of the sodium nitrate used in cured meats, except for that used in slow cured country ham.
sodium nitrate: InChI=1/NO3.Na/c2-1(3)4;/q-1;+1
sodium nitrite: InChI=1/HNO2.Na/c2-1-3;/h(H,2,3);/q;+1/p-1/fNO2.Na/q-1;m