This was posted by Fred on TexasBBQRub forum....below is the main information, here is the link to thread if you want it http://forum.texasbbqrub.com/showthread.php?t=28977&highlight=nitrates
Nitrogen dioxide (NO2) is among the compounds formed in the high heat combustion of wood, charcoal, and even propane. As these compounds land on the surface of meat, especially cool moist meat from the fridge, some, including nitrogen dioxide, are moved deeper into the meat as cells lower in the smoke compounds pull them in with a diffusion and absorption process. The cells are simply seeking equilibrium. The process is the same as when someone lights a cigar in a room. All the smoke starts out near the cigar, but eventually it spreads throughout the room as it achieves equilibrium. After a while it penetrates clothes, furniture, and even food. Because it is water soluble, cigar smoke will get into wet things first, like your wife's eyes. Before long you and your cigar will be seeking equilibrium in the garage.
The smokering in meat is caused by four things: (1) low temperature cooking, (2) combustion of the wood at high temperatures to form nitrogen dioxide, (3) nitrogen dioxide, and (4) moisture on the surface of the meat to help move the water soluble nitrogen dioxide into the meat. When these conditions are met, nitrogen dioxide in wood smoke reacts with the pigment myoglobin in meat to form nitrites and
nitrates. These are the same compounds added to hot dogs and other cured meats to preserve them and they also give them their pink color.
When cooking ribs, the moist meat absorbs smoke. Less smoke is absorbed as the cooking continues because the surface of the meat begins to seal and becomes saturated with smoke. For this reason putting a pan of water in a smoker helps create a smokering. In fact some smokers, called water smokers, have water pans built in.
Most of the smoke flavoring occurs in the first hour or two of cooking so adding wood to the fire late in the cook doesn't create as much flavor. It also allows moisture to escape. It's better to just leave the door closed.
A faux smokering can also develop without smoke if you cook low 'n slow. When meat is cooked fast, the proteins in the muscle and myoglobin denature at the same time and combine to turn brown. When cooked slowly, the muscle proteins finish denaturing before the naturally pink myoglobin denatures and so the meat remains pink. You can occasionally see this phenomenon in braised meat like a beef stew. It may have been cooked for hours in a liquid at low temps, yet the meat will still be slightly pink inside.
On the other hand, some meats cooked low and slow in a smoky environment in an electric smoker will not develop a smokering. That is partially because the wood smolders at a low temp in electrics. Experts at cooking in electric smokers will add a charcoal briquette as well as wood chunks to create the correct atmospheric conditions for a smokering.
This was posted by Mike Oliver on TexasBBQRub forum....below is the main information, here is the link to thread if you want it http://forum.texasbbqrub.com/showthread.php?t=28393&highlight=nitrates
I think temp of the meat temp dictates the thickness of the ring the longer it stays cool (below 140'ish) supposed to be the magic number .
The Smoke comes from NITRIC OXIDE / NITRITES ?? a chemical reaction not the actual smoke, charcoal actually gives you a better smoke ring. I will look for the write up on nitrites and post it.
here is some of one, cant find the good ones any more...
Its not nitrites that cause the pink smoke ring, its actually nitric oxide. Nitrites get converted to nitric oxide. Nitric oxide gets absorbed by myoglobin in the meat. If the meat is cold-cured, such as a country style ham, it will have a deep red color. This deep red color is caused by the nitric oxide myoglobin. When the myoglobin gets heated, aka cooked, it turns pink yielding the beloved smoke-ring.
Given the fact that nitric oxide is a byproduct of combustion, it seems logical to conclude that there are no nitrites or nitrates in smoke. Its the nitric oxide (NO) gas thats created by burning wood that causes the smoke-ring.
