建立了一种利用毛细管电泳测定绿茶酶解液中主要还原糖的方法。针对绿茶浸提液中可能含有的麦芽糖、乳糖、木糖、阿拉伯糖、葡萄糖、鼠李糖、半乳糖、甘露糖、半乳糖醛酸等9种主要还原糖,当被1-甲基-3-苯基-5-吡唑啉酮(PMP)衍生后,在电压21 kV,硼酸浓度200 mmol/L,pH值11.0和柱温25℃的条件下可实现基线分离。对这9种还原糖衍生物作标准曲线,在0.5~10 mmol/L浓度范围内线性相关度R2为0.9939~0.9994,最低检测极限范围是0.09~0.23μmol/mL,9种还原糖衍生物加标回收率在94.04%~101.9%。应用该方法测定绿茶酶解液中主要还原糖的组分和含量,得出酶解液中主要含有木糖、阿拉伯糖、葡萄糖、半乳糖和半乳糖醛酸5种,它们的浓度随着复合水解酶的来源不同而不同。

A method for determination of reducing carbohydrates in the green tea enzymatic hydrolysate by capillary zone electrophoresis( CZE) was established. Nine reducing carbohydrates which may be existed in the green tea enzymatic hydrolysate were derivatized with 1-phenyl-3-methyl-5-pyrazolone( PMP),and baseline separated by CZE under the condition of 200 mmol /L borate buffer pH 11. 0 and running voltage 25 kV at temperature 25 ℃. The standard curves of main reducing carbohydrate derivative in the green tea including maltose,lactose,xylose,arabinose,glucose,rhamnose,galactose,mannose and galacturonic acid showed good linearity in the range of 0. 5 ~ 10mmol /L and the R2value equivalent to 0. 9939 ~ 0. 9994. The minimum limit point of determination ranged from 0. 09to 0. 23 μmol /mL and quantitative recoveries of the nine reducing carbohydrates ranged from 94. 04% to 101. 9%.The optimized CZE method was found to be feasible to examine the compositions and content of reducing carbohydrates in the green tea extracts with enzyme treatment. The result showed that the enzymatic solution mainly contained five kinds of reducing carbohydrates including xylose,arabinose,glucose,galactose and galacturonic acid and their concentrations varied with different composite hydrolase source. The method for determination of reducing carbohydrates in the green tea enzymatic hydrolysate was characterized by easy operation,high sensitivity and good accuracy.