In December 2012 the IFST (Institute of Food Science & Technology) published an interesting statement on Stevia. Below some of the highlights (direct excerpts from text). Read on to review the entire report.
- Stevia is widely cultivated in South America, but much of the world’s commercial supply currently originates in Asia.
- Stevia has been subject to 50 years of biological and toxicological investigation. (…)Today, there is a large number of studies on stevia in the scientiﬁc literature which conﬁrm its safety. In 2008, JECFA established a permanent Acceptable Daily Intake (ADI) for puriﬁ ed steviol glycosides of 4 mg/kg body weight/day (expressed as steviol) and validated the safety of puriﬁed steviolglycosides for use as a food and beverage sweetener. In 2010, the European Food Safety Authority (EFSA) also concluded that steviol glycosides are safe.
- Until recently, synthetic high-potency sweeteners (HPS) were the only possible solution to the problem of removing sugars from a number of products without loss of sweetness. Steviol glycosides (E960) has recently been added to the European Union (EU) list of permitted sweeteners. This means that, for the ﬁrst time, there is available a non-caloric HPS, derived from nature, that has a taste quality good enough for it to be a signiﬁcant source of sweetness in soft drinks and other products.
- The most abundant of these molecules in the wild-type plant is stevioside, but the less-plentiful rebaudioside A (reb A) is widely held to be the better tasting (Fry, 2012; Phillips, 1987). There are in addition many other glycosides, but these two are key. Because of the taste preference for reb A, conventional plant breeding programmes have been directed over many years to increasing the yield ofof this compound. Dried leaves of Stevia rebaudiana typically contain about 7–15% by weight steviol glycosides (Carakostas et al. 2011). Of this, 40% might be reb A in a modern cultivar (Morita and Bu 2000a; 2000b; Morita et al. 2009).
- The glycosides are extracted by steeping dry leaves in warm water, ﬁltering the extract free of solid material, and purifying the resultant solution by a combination of chromatography and crystallisation from water–alcohol solutions. This results in a crude extract comprising a mixture of glycosides in variable proportions, generally containing predominantly stevioside and rebaudioside A. Such extracts may be used directly in some locations, but are normally further reﬁned by additional recrystallisation to create ingredient-grade HPS that meet the purity requirements of Western markets.
Click here view the entire report.