Astringent, one kind of fruit acid, mainly achieved form citrus fruits (especially lemon). It can be used as the source of sour taste for some food or drink, and also can be used as a natural preservative. It plays an indispensable role of citric acid cycle in human body.
It general, fruit acidic is always said as weak acid, had it not been stressed that containing fruit acid formulations, it can only be used as PH regulator, not has fruit acid effects.