Inhibiting Microorganisms

• Nitrate preserves foods because it inhibits the growth of bacteria that could cause food to rot. As food decays, some becomes spoiled with botulism, which causes food poisoning and is fatal in extreme cases. Nitrates added to food dry out the environment (the food), leaving nothing to encourage the bacterial growth. Some bacteria thrive in oxygen-free settings, but nitrates have been shown to effectively prevent the growth of those strains of bacteria as well.
  
  

Curing Meat

• Nitrates have been added to an assortment of different foods, mostly dehydrated or canned. But they are extensively used to cure meats, including sausage, bacon and hot dogs. Nitrates added to these types of foods not only discourage the growth of microorganisms, they protect the flavor and the color of the meats, making them look fresh and taste better for much longer.
  
  

Premixed Nitrates

• You can preserve foods yourself using nitrates. Unless you are a trained chemist, it's best to stick to commercial cure mixes that can be purchased in most grocery stores. These premixes are easy to use and are much safer than attempting to use pure nitrate, which can have toxic effects. They are mixed with salt, allowing you to treat the meat you're curing with the premix and without concern for excess nitrate being added to the food.
  
  

Health Concerns

• Health concerns have been associated with nitrates over the years because of a link between nitrosamines and cancer. Although nitrate is essentially harmless in small doses and by itself, it is possible for it to be converted in your body into nitrite, which can then form nitrosamines. As with most foods and beverages, though, moderate consumption of foods containing nitrates wouldn't be cause for concern over developing cancer. Further precautions can be taken, such as getting enough vitamin C, which can hinder nitrite converting to nitrosamines. Another reassurance is that cured meats produced for public purchase and consumption undergo frequent analysis and must test free from toxic and cancer-causing substances.