Safety of the proposed amendment of the specifications for enzymatically produced steviol glycosides (E 960c): Rebaudioside D produced via enzymatic bioconversion of purified stevia leaf extract

The EFSA Panel on Food Additives and Flavourings (FAF Panel) provides a scientific opinion on the safety of a proposed amendment of the specifications of enzymatically produced steviol glycosides (E 960c) with respect to the inclusion of rebaudioside D produced via enzyme-catalysed bioconversion of purified stevia leaf extract. Rebaudioside D (95% on dry basis) is produced via enzymatic bioconversion of purified stevia leaf extract using uridine diphosphate (UDP)-glucosyltransferase (UGT) and sucrose synthase enzymes produced by the genetically modified yeast K. phaffii UGT-A, that facilitates the transfer of glucose to purified stevia leaf extract via glycosidic bonds. The same enzymes from K. phaffii UGT-A may be used in the manufacturing process of the food additive, rebaudioside M produced via enzyme modification of steviol glycosides from stevia (E 960c(i)). The Panel considered that separate specifications would be needed for this food additive produced via the manufacturing process described in the current application, aligned with those already established for E 960c(i). The Panel concluded that there is no toxicological concern for Rebaudioside D produced via enzymatic bioconversion of purified stevia leaf extract using UDP-glucosyltransferase and sucrose synthase produced by a genetically modified strain of the yeast K. phaffii. However, based on the available data, the Panel could not exclude the possibility that some residual amount of DNA coding for the kanamycin resistance gene could remain in the final product. Should this gene propagate in microbiota due to the presence of recombinant DNA in the final product, this would be of concern. Therefore, the Panel concluded that the safety of Rebaudioside D produced via this enzymatic bioconversion was not sufficiently demonstrated with the available data given that the absence of recombinant DNA was not shown.