General Stevia

There are many patents and journal articles that describe processes to produce the principal sweet diterpene glycosides stevioside and in particular, rebaudioside A. Many of the reported methods of production require the use of ion exchange columns or gases and are not satisfactory if the scale-up to commercial quantities are required. Most methods for extraction and purification of the sweet diterpene glycosides from Stevia use complicated processing of the crude extracts. Generally, the recovery processes of the principal two diterpene glycosides stevioside and rebaudioside A involve ... 

Pure stevioside is a white hygroscopic powder (The Merck Index, 1976) and commercial extracts vary from cream to tan powders. The solubility of pure stevioside in water is 1.2 g/1 (The Merck Index, 1976). Commercial extracts have solubilities that range from 300 to 800 g/1 (Stevia Corporation, 1986). The relative sweetness of stevia extracts varies from 15 to 300 (O Donnell, 1983 Richard, 2002 Tunaley et al., 1987 ) The taste of stevioside is characterised by a lingering sweetness and liquorice, bitter off-taste (O Donnell, 1983). This limits its commercial application and it is generally not used as a sole sweetener in most applications. 

Two more longipinane derivatives (218) and (219) have been isolated from Stevia species.A full paper on the chemistry of vulgarone A (220) and B (221) has been published." In keeping with the general rule that enantiomeric sesquiterpenoids are often found in liverworts, Matsuo have identified the... 

There have never appeared reports proving that the use of Stevia or stevioside enhances the number of cancers in populations, even after a very long time of use (eg. Paraguay more than 500 years, Japan more than 25 years, South-Korea 15 years, Brasil 12 years, China 11 years or the USA since 1995 admitted as a dietary supplement). Thus the general conclusion is that Stevia and its sweeteners stevioside and rebaudioside A are completely safe. 

Reviews of safety and toxicity information on stevia and the compound stevioside indicate that both are generally safe, with no adverse effects noted (Geuns 2002,2003). 

---