Where does Lactic acid fermentation occur?
I can tell you lactic acid build-up occurs in the muscles and is released as a waste product into the blood after working the muscles. This is what causes soreness and muscle fatigue after working out strenuously. What I think you are talking about is the process of the body to turn sugars such as fructose into energy that can be used in cells and can be metabolized. Lactic acid fermentation occurs in cardiac muscles, the liver and any other oxygen starved muscles.