Stevioside is the main sweet substance of stevia rebaudiana leaves, and the extract is in the form of crystals, which is also called stevioside when used as a food sweetener. Stevia rebaudiana is a sweet taste familiar to most people, and it is also a common perennial herb at the junction of Paraguay and Brazil in South America. Stevia rebaudiana leaves contain a sweet substance called steviosin. The refined steviosin is colorless and tasteless crystal, and its sweetness is about 300 times that of sugar. Because of its low calorie, easy to dissolve in water or alcohol, heat-resistant, it can be said that it is a sugar product without calories, and it is a commonly used sweetener in diet or diet food for diabetic patients. Stevia rebaudiana is called "Kahei" (Gulani language, meaning "sweet grass") in Paraguay, which is used to add sweetness to Paraguay tea (yerba mate) and so on.

Stevioside, alias Stevioside. Molecular formula: C38H60O 18. Properties: white or yellowish powder, soluble in water, ethanol and methanol, insoluble in organic solvents such as benzene, ether and chloroform, extremely sweet, like sucrose, slightly astringent, about 200 times sweeter than sucrose. It is stable to heat, acid, alkali and salt under general food processing conditions. When the pH value is greater than 9 or less than 3, it will decompose due to long-term heating (100℃), and its sweetness will decrease. It is not fermentable, and only a few enzymes can hydrolyze it. Uses: Sweetener.