I saw the host on a cooking show claim that using seltzer in a marinade will help the flavors better penetrate meat via the carbonation. Is there any truth to this, and how would it actually work? e.g. would the bubbles carry bits of flavor material, or somehow open "pores" in the meat...?
I would strongly doubt that the bubbles themselves would have any mechanical effect on flavor. However, seltzer or soda water has a acidic pH, usually between tomato and orange juice. This could account for any tenderizing action. The addition of salts to some seltzers might also account for apparent changes in flavor.
I have not seen a recipe that contains seltzer , but I would imagine that it is the same reaction that MSG has in Asian cooking, where restaurants can use cheap cuts and tenderizes the meat before cooking. Most MSG is banned in restaurants now. I myself have used coca cola in marinades in meats like ribs and pork belly as the acids does the same thing to the meat tendons as well as giving sweetness to the meat.
I use sparkling waters when I brine. It looks like it has a PH level of between 3 and 4 so it is acidic. I still add salt (which bubbles when added) and lemon juice for added acid.
One thing that may be a contributing factor is those bubbles. Well not the bubbles themselves but the escaping gas.
If the container being used is sealed you are increasing the pressure inside of that container which should assist in penetration.
I use ziplock bags so the aid can't be all that much but the results are always a very juicy piece of meat. Or fish as I am doing right now (a good portion of dill is sitting in there too).
Was in Missoula Montana at local hospital and my spouse got talking with local Native American Indian about hunting and cooking. She said after cooking wild turkey she submerged in ginger ale/ seltzer mix for 3 days and it makes meat very tender & soft......especially legs of wild turkey which there is no other way to soften. (According to her) ......she had to be at least 70yrs and had no teeth....so I image the meat did become soft as that would be the only way she could eat it.