By Lynn A. Kuntz, Editor-in-Chief
Stevia’s history started in Paraguay, where the indigenous people used leaves of the plant known as kaa he-he (“sweet herb”) to sweeten mate beverages and herbal teas, or chewed them for their sweet taste. A more-widespread awareness of its sweetening power started in the late 1800s to early 1900s. This led to its adoption by the Japanese as a natural high-intensity sweetener in the 1970s, when Morita Kagaku Kogyo Co., Ltd. commercialized its stevia sweetener and established an integrated production system from cultivation to extraction and refinement.
Fast-forward to 2010, when stevia-based sweeteners are approved for food use in a number of countries across the globe: Japan, Korea, China, Taiwan, Australia, Russia, Ukraine, Kazakhstan, Malaysia, Indonesia, Latin America and the United States. In April 2010, the European Food Safety Authority (EFSA) issued a positive opinion on the safety of steviol glycosides.
“The GRAS notification, GRN 252, received a ‘no objection letter’ from FDA, which made reb A (rebaudioside A) purity of more than 95% GRAS in the United States. A recent GRAS notification (GRN 287) asked for GRAS status of stevia extract containing more than 95% of total steviol glycosides and received a ‘no objection letter’ from FDA,” explains Sidd Purkayastha, technical director, PureCircle Limited, Oak Brook, IL. Any other stevia products marketed here currently follow the self-affirmed GRAS route.
How sweet it is
The plant that supplies the popular sweetener, Stevia rebaudiana Bertoni, belongs to the aster family, Asteraceae, and is one of 150 to 300 species of perennial herbs and shrubs. Stevia plants are cultivated today in Paraguay, Mexico, Central America, Japan, China, Malaysia and South Korea, as well as some parts of Europe.
Stevia rebaudiana produces a number of sweet compounds. The leaves contain a complex mixture of naturally sweet diterpene glycosides. These include stevioside (4% to 13% dry weight); steviolbioside (trace); rebaudiosides A (2% to 4%), B (trace), C (1% to 2%), D (trace) and E (trace); and dulcoside A (0.4% to 0.7%), according to a 1999 EU safety review (“Opinion on Stevia Rebaudiana Bertoni Plants and Leaves”). “Dried leaf contains around 12% to 18% total steviol glycosides (TSG),” says Purkayastha. “Depending on the variety of stevia leaves, either stevioside or reb A is present in the highest quantity.”
