Steviol glycosides from Stevia

What it is

Steviol glycosides (E960a) are the sweet chemical compounds extracted from the leaves of the Stevia rebaudiana plant. They are up to 300 times sweeter than sugar and contain zero calories.

How it is used in food

Steviol glycosides deliver 200–300 times the sweetness of sugar with no calories and no rise in blood glucose or insulin, which makes them useful for diabetic and reduced-sugar formulation. They are stable to heat up to around 200 °C and across the pH range of ordinary foods, so unlike aspartame they survive baking, pasteurisation and long storage in acidic soft drinks. They are also non-cariogenic — oral bacteria cannot ferment them into tooth-eroding acid.

• Diet sodas and iced teas
• Yoghurts and low-sugar dairy desserts
• Tabletop sweeteners (often blended with erythritol)

Health and safety

Unlike artificial sweeteners, Stevia is extracted from a plant, giving it a strong "clean label" appeal. Extensive toxicology studies have shown it is safe, non-toxic, and does not spike blood sugar.

JECFA set a group ADI of 4 mg per kg body weight per day expressed as steviol equivalents, and EFSA's 2010 opinion reached the same figure. Metabolism explains the safety margin: the glycosides are not absorbed intact but are hydrolysed by colonic bacteria to steviol, absorbed, conjugated in the liver to steviol glucuronide and excreted in urine. Earlier concerns about mutagenicity of a metabolite were not reproduced in mammalian systems, and long-term feeding studies showed no carcinogenicity.

Regulatory status

Identification on labels

E-number

E960a

Also printed asStevia extract

Alternatives to this additive

• E955: Sucralose — An artificial sweetener that provides a taste much closer to real sugar without the bitter aftertaste.

How it is made

The stevia leaves are steeped in hot water (like tea), and the sweet compounds are purified out of the liquid using alcohol and ion-exchange resins.

1. Extraction — Stevia leaves are crushed and steeped in hot water.
2. Purification — The extract is filtered and crystallized to isolate the pure steviol glycosides (like Rebaudioside A).

Worth knowing

The Guaraní peoples of Paraguay and Brazil sweetened yerba maté with stevia leaves — ka'a he'ê, "sweet herb" — for centuries before European science described the plant. Japan commercialised stevia in the 1970s, but the EU only authorised it in 2011, having previously rejected it on the grounds that the toxicology package was incomplete.

Conclusion

E960a is highly regarded as a safe, natural alternative to sugar. Its only real drawback is culinary: highly purified stevia extracts can trigger bitter receptors on the tongue, leaving a distinctive metallic or licorice-like aftertaste.

References

• EFSA opinion on steviol glycosides — EFSA