Sweetness is a complex physical, chemical, and physiological process in which sweetener molecules stimulate taste buds. Sweet and low is called sweetness, is an important indicator of sweeteners. The sweetness can not be measured quantitatively by physical and chemical methods, but can only be judged by the sense of people's taste. To compare the sweetness of sweeteners, sucrose is generally chosen as the standard, and the sweetness of other sweeteners is relative to the sweetness obtained by comparison with it. There are two ways to determine relative sweetness: one is to match the sweetener to a minimum concentration that can be felt sweet, called the limit concentration method, and the other is to match the sweetener to a solution with the same concentration as sucrose, and then compare the sweetness of the sweetener with sucrose solution as the criterion, called the relative sweetness method.