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Stevia rebaudiana
Rebaudioside - A
Steviol glycoside甜菊糖苷
Stevia (/ˈstiːvɪə/, /ˈstiːvjə/ or /ˈstɛvɪə/)[1][2][3] is a sweetener and sugar substitute extracted from the leaves of the plant species Stevia rebaudiana.
The active compounds of stevia are steviol glycosides（甜菊糖苷） (mainly stevioside（甜菊苷） and rebaudioside（甜菊双糖苷）), which have up to 150 times the sweetness of sugar,[4] are heat-stable, pH-stable, and not fermentable.[5] These steviosides have a negligible effect on blood glucose, which makes stevia attractive to people on carbohydrate-controlled diets. Stevia's taste has a slower onset and longer duration than that of sugar, and some of its extracts may have a bitter or licorice-like aftertaste at high concentrations.
The legal status of stevia extracts as food additives and supplements varies from country to country. In the United States, stevia was banned in 1991 after early studies found that it might be carcinogenic; after additional studies, the FDA approved some specific glycoside extracts for use as food additives in 2008.[6] The European Unio approved stevia additives in 2011,[7][8] and in Japan, stevia has been widely used as a sweetener for decades.[9]
Extraction
Rebaudioside A has the least bitterness of all the steviol glycosides in the Stevia rebaudiana plant. To produce rebaudioside A commercially, stevia plants are dried and subjected to a water extraction process. This crude extract contains about 50% rebaudioside A. The various glycosides are separated and purified via crystallization techniques, typically using ethanol or methanol as solvent.[57]