双酶偶联转化果糖制备含有稀少糖的混合糖液

Production of sugar syrup containing rare sugar using dual-enzyme coupled reaction system

酶转化法是功能性稀少糖生产的重要途径,但单一稀少糖转化酶的转化率普遍较低。文中提出构建双酶偶联转化系统提高转化效率的思路,即利用D-阿洛酮糖3-差向异构酶(D-psicose 3-epimerase,DPE)和L-鼠李糖异构酶(L-rhamnose isomerase,L-RhI)双酶偶联反应,催化D-果糖生成D-阿洛酮糖和D-阿洛糖等功能性稀少糖。DPE和L-RhI加酶量的比例为1∶10,其中DPE的浓度为0.05 mg/mL;转化反应的最佳温度为60℃,最适pH为9.0。当D-果糖浓度为2%时,反应10 h达到平衡,此时D-阿洛酮糖和D-阿洛糖的产量分别为5.12和2.04 g/L。利用文中提出的双酶偶联系统可以将果葡糖浆等富含果糖的低附加值原料转化为含有功能性稀少糖的高附加值混合糖液。

Enzymatic conversion is very important to produce functional rare sugars, but the conversion rate of single enzymes is generally low. To increase the conversion rate, a dual-enzyme coupled reaction system was ueve^up^u. Dual-enzyme coupled reaction system was constructed using D-psicose-3-epimerase （DPE） and L-rhamnose isomerase （L-RhI）, and used to convert D-fructose to D-psicose and D-allose. The ratio of DPE and L-Rhl was 1：10 （W/W）, and the concentration of DPE was 0.05 mg/mL. The optimum temperature was 60 ~C and pH was 9.0. When the concentration of D-fructose was 2%, the reaction reached its equilibrium after 10 h, and the yield of D-psicose and D-allose was 5.12 and 2.04 g/L, respectively. Using the dual-enzymes coupled system developed in the current study, we could obtain sugar syrup containing functional rare sugar from fructose-rich raw material, such as high fructose corn syrup.