Transglycosylation of Mogroside Ⅴ, a Triterpene Glycoside in Siraitia grosvenori, by Cyclodextrin Glucanotransferase and Improvement of the Qualities of Sweetness

摘要

Mogroside Ⅴ (MV), a main sweet triterpene glycoside in the extract of the fruit of Luo-han-guo (Siraitia grosvenori Swingle), was transglycosylated by cyclodextrin glucanotransferases (CGTases) using starch as a donor substrate. CGTases from Bacillus macerans, B. circulans, B. stearothermophilus and Thermoanaerobacter sp. were effective for the transglycosylation of MV. It was appropriate for the production of glycosylated MV to react 9% (w/v) MV with 20% (w/v) tapioca starch and B. macerans enzyme (30 U/g-starch) at 50℃ and pH 6.5. Under these conditions, the reaction finished within 24 h and more than 90% of a glycosylation yield was attained. Three products that have 1-3 additional glucose residues were identified as transglycosylation products by mass spectrometry. The greater number of glucose residues introduced, the less intensity of sweetness compared to MV was estimated by sensory evaluation. However the qualities of sweetness such as bitterness, after-taste, and peculiarity were improved by transglycosylation.%羅漢果（Siraitia grosvenori Swingle）エキス中に存在す る甘味トリテルペノイド配糖体の主成分であるモグロシ ド Ⅴ（MV）を，デンプンを供与体基質としてシクロデキ ストリングルカノトランスフエラーゼ（CGTase）の転移 反応で配糖化した．Bacillus macerans, B. circulans, B. stearothermophilus はょびThermoanaerobacter属由来の CGTaseはMVを転移反応で効率的にグリコシル化した． グリコシル化には9％（w／v）MV，20％のタピオカデン プンに B・macenrans の CGTase（30単位／gデンプン）を 50℃,pH 6.5で24時間作用させ繄龊悉m当であり，こ の条件下では24時間以内に最大約90％という配糖化率 が達成できた．