Extracts of Siraitia grosvenorii (Swingle), in Chinese known as Luo Han Guo (LHG), is authorized for use as a natural sweetener . LHG is rich in mogroside V that contains five glucoses, but also contains mogroside IIIE and analogues with fewer than three glucose units that cause an unpleasant aftertaste, limiting the use of the extract. Snailase was applied here to convert mogroside V in LHG extract in favor of siamenoside I formation, the sweetest mogroside with a taste similar to sucrose . For application, snailase was immobilized by adsorption to NKA (a macroporous resin), resulting in 10.9 U per g of adsorbed protein. Reuse of the NKA-adsorbed snailase was demonstrated for four cycles, and a continuous production of improved LHG extract at a 0.5 L scale had a productivity of 68.4 g/(L⋅day). The resulting product containing over 50% siamenoside I displayed an improved taste profile with satisfying safety toward HEK293T cells.
A new compound, α-siamenoside I (α-SI), with a glucose unit selectively bound to the 6-hydroxyl group of the 24- O -β-glucosyl moiety of mogroside IIIE by α-1,6-glucosidic bond, was bio-created by two screened cyclodextrin glycosyltransferases with a maximum yield of 59.3%. Compared to mogroside IIIE, α-SI showed a significantly increased sweetness intensity (508 times sweeter than 5% sucrose), which is superior to siamenoside I (SI), the sweetest triterpenoid saponin isolated from Siraitia grosvenorii to date. Sensory evaluation showed that the taste quality of α-SI also was obviously better than mogroside IIIE. In addition to α-SI possessing a good stability similar to that of SI, it also did not cause a significant decrease in cell viability at a concentration of 200 μg/mL and had a negative influence on islets function at 1 μM. All of these preliminarily results pave the way for promoting α-SI as a potential low-calorie sweetener.
危险品化学品经营许可证（带存储）