Effect of shaking velocity on mono-glycosyl-stevioside productivity via alternansucrase acceptor reaction

Abstract In this study, effect of shaking velocity on mono-glycosyl-stevioside production by Leuconostoc citreum SK24.002 alternansucrase acceptor reaction was investigated, with four different level of shaking velocity (75, 100, 125 and 150 rpm) up to 24 h at 25 °C, using sucrose as donor and stevioside as acceptor. The results revealed that mono-glycosyl-stevioside yield significantly increased with increase in the reaction shaking velocity and reached maximum yield of 3.78 ± .02 mg/mL at 150 rpm shaking velocity after 6 h of reaction. And an increase in the reaction shaking velocity up to 150 rpm reduced the final reaction time and increased the productivity of mono-glycosyl-stevioside product such that the high quantity of mono-glycosyl-stevioside product was produced in only 6 h rather than 24 h. The mono-glycosyl-stevioside product was completely separated using macroporous resin AB-8 flowed by semi-preparative HPLC. Macroporous resin AB-8 showed high selectivity and capacity toward mono-glycosyl-stevioside. The structure of mono-glycosyl-stevioside was characterized, as 13-{[α- d -glucopyranosyl-(1→6)-β- d -glucopyranosyl-(1→2)-β- d -glucopyranosyl]oxy}kaur-16-en-19-oic acid β- d -glucopyranosyl eater, a corroding to extensive 1D and 2D NMR (1H and 13C, COSY, HSQC, HMBC) and mass spectral data.