E960b - Rebaudioside from multiple gene donors expressed in Yarrowia lipolityca

Steviol glycosides are the intensely sweet compounds that make the leaves of Stevia rebaudiana taste sweet — several hundred times sweeter than sugar, with no calories. The catch is that the sweetest and cleanest-tasting of them, rebaudioside M, occurs in the leaf in tiny quantities, so extracting it from plants at scale is impractical.

E 960b solves that by fermentation. A yeast, Yarrowia lipolytica, is engineered to carry the plant's own biosynthetic enzymes and grown on a sugar feedstock, producing rebaudioside M directly. The molecule is identical to the one in the leaf; only the route differs. The point of the exercise is taste: rebaudioside M lacks most of the liquorice-like bitter aftertaste that limited early stevia products.

Reduced-sugar and no-added-sugar soft drinks, flavoured waters, yoghurts and dairy desserts, table-top sweeteners, confectionery and chewing gum.

Steviol glycosides from fermentation are authorised in Great Britain as E 960b, within the group “E 960a – E 960c: Steviol glycosides”. The FSA register records a determination of 19 February 2026 that authorised a second production method — E 960b(ii), rebaudioside M from fermentation using Saccharomyces cerevisiae — and renumbered the existing Yarrowia lipolytica authorisation to E 960b(i). The register notes no substantive change to the scope or conditions of the existing authorisations.

The acceptable daily intake for the steviol glycoside group is 4 mg per kg of body weight per day, expressed as steviol equivalents, set by EFSA in 2010 from a two-year rat carcinogenicity study. EFSA considered proposals to raise it to 6 or 16 mg/kg in 2024 and concluded there was insufficient justification to do so, noting that the higher figures would increase ADI exceedance among toddlers.

EFSA has repeatedly flagged that toddlers at the 95th percentile can exceed the steviol glycoside ADI. Separately, the World Health Organization advised in 2023 against using non-sugar sweeteners for weight control, on the basis of long-term outcome evidence rather than a toxicological concern.

• FSA Register of Food Additive Authorisations — E 960b
• EFSA (2024), Extension of authorisation of steviol glycosides (E 960a–d) and modification of the ADI for steviol
• EFSA (2023), Safety of steviol glycosides, predominantly Rebaudioside M, produced by fermentation using Yarrowia lipolytica VRM