Steviol glycosides from Stevia – Sweet and Calorie Free
Stevia rebaudiana Bertoni, named after the botanist Moisés Santiago Bertoni, is a perennial herb growing in South America whose leaves taste very sweet thanks to their content of steviol glycosides. The steviol glycosides produced from Stevia leaves can be used as a sweetener to replace sugar in foods and beverages.
The most important steviol glycosides responsible for the sweetness are stevioside, rebaudioside A, rebaudioside C and dulcoside A. Steviol glycosides are free of calories and non-cariogenic. They do not affect blood sugar levels and so steviol glycosides are suitable for diabetics. These days, the Stevia plant is grown mainly in America, Canada, China and above all Japan. Japan has been industrially marketing steviol glycosides for the last 30 years. While the American Food and Drug Administration (FDA) approved rebaudioside A, or Reb A, at the end of last year, the EU has not yet approved Stevia as a food or food additive. The one exception is France, who has approved Reb A.
Legislation in Switzerland
Switzerland has already approved a number of products with the sweetener steviol glycoside. The “pioneer” in this case was Umberto Leonetti of Storms. The innovative company was the first Swiss company to receive approval from the Swiss Federal Office of Public Health (FOPH) to use steviol glycoside originating from Stevia as sweetening agent. Storms then released Europe’s first drink sweetened with steviol glycoside (Storms One). More drinks containing steviol glycosides were soon to follow, such as the ice tea Nice T. Swiss food law classifies steviol glycosides among the additives, and more specifically the sweeteners, because of their technological use. Since the glycosides are still not listed as approved additives in Annex 1 of the Swiss Additives Ordinance, their use must be authorized in each case. As of autumn 2008, licence to use a JECFA-standardized Stevia extract in food can be applied for from FOPH. (JECFA is the Joint FAO/WHO Expert Committee on Food Additives.)
Producing steviol glycosides from Stevia
Industrially, the water-soluble steviol glycosides are extracted from Stevia leaves using water or steam. They are then separated and further concentrated over a number of different processes, using ion-exchangers, for example. The product is typically spray or vacuum dried into a powder before packaging.
Properties of steviol glycosides
Overall, steviol glycosides are highly soluble. The glycosides are also stable at high and low temperatures, so they can be used in cooking and baking as well as in frozen products. Another advantage is their stability over a broad pH range, which means Stevia products can even be used in soft drinks. The relative sweetness depends on the composition of the extract, but typically, steviol glycosides are about 200–450 times sweeter than sugar. The sweetness of steviol glycosides is long lasting, with a delayed fall-off. If used at high concentrations, steviol glycosides can have the sensory drawback of a liquorice-like bitter taste, which could be noticeable in certain products. Whether and how much this bitter taste is perceived as disturbing depends on the composition of the steviol glycosides and the quantity used in the end product. The bitter taste can be masked with fructose and lactose, for example, and flavour producers already offer masking solutions. It has been described that steviol glycosides can reinforce fruit flavours as a useful added effect. Interactions with other ingredients in drinks have not been observed for steviol glycosides so far. The stability of steviol glycosides in the end product is generally very good.
Consistent quality guaranteed
A high quality steviol glycoside stands out not only for purity but also for consistent quality. The ratios of the different steviol glycosides in a given plant can vary greatly depending on the conditions in which the plant grows. Accordingly, the compositions of many steviol glycosides also vary greatly. Only a raffinate of consistently standardized quality can guarantee consistent product quality. Possible applications for steviol glycosides include drinks, dairy products, pastries, sweet desserts, jams and marmalades, confectionary or ketchup.
Stevia at a glance
- sweetener from Stevia
- free of calories
- alternative to sweetening with sugar or other sweeteners
- mild on teeth
- low glycaemic index, suitable for diabetics
- highly soluble in water
- stable over a broad pH range, even in soft Drinks
- withstands heating and freezing
Available product variations
- steviol-glycosides (for example steviol glycoside 95% or rebauudiosid A 98%)
- sweetener with steviol glycosides from Stevia