What it is
Vinegar and lactic-acid salts dosed into deli meats and hot dogs to hold off Listeria and stretch shelf life.
Why your biology objects
The molecules are benign — lactate and acetate are things your body makes and burns (lactate is a fuel, acetate is vinegar). The tell is that they're added as an isolated anti-microbial system instead of arriving through fermentation. The bigger issue is usually the processed meat they're keeping fresh.