The internationally accepted JECFA stipulates that the pH value is between 4.7 and 7.0. Generally speaking, the pH value is between 5 and 6. So it's a little sour. But it is very stable in acid-base environment. Under the condition of PH3 (room temperature), 180 days basically has no decomposition loss and no precipitation. When heated to 100℃ in the range of PH3-9, 1 hour remained unchanged.