Good afternoon. Maillard reaction will still occur below PH3, but its speed will slow down. Its main condition is that contact with oxygen will inevitably oxidize to produce various heteropoly acids. The anoxic environment will greatly slow it down. Maillard is generally irreversible. When the PH value is less than 3, I cut fresh slices of lemon and hawthorn fruit for analysis, and the taste is simply sour and refreshing. Unfortunately, Maillard still makes them look bad. Please refer to.