魔芋葡甘聚糖测定方法的比较研究

A Comparative Study on Determination of Glucomannan from Konjac Powde

在用DNS法测定魔芋葡甘聚糖的含量过程中,以丙三醇代替苯酚。在波长λ为556 nm,水浴的显色时间为5 min,显色温度90-100℃,稳定时间为1-1.5 h条件下,同一样品用丙三醇显色法测得葡甘聚糖的含量为73.44%,回收率为98.6%,精密度为0.98;苯酚比色法测得葡甘聚糖的含量为70.87%,回收率为102.7%,精密度为0.93。结果表明,该方法（DNSⅠ）具有方便、安全、成本低等优点,适合于常规实验室魔芋粉葡甘聚糖定量的测定。

The author tried to use the DNS colorimetry that contain glycerol instead of phenol to determine content of konjac glucomannan. The experiment indicated, analysis konjac glucomannan content optimum condition： the wave length lamda is 556nm, in the coloring time is 5 min, the coloring temperature range is 90-100 ℃, the settling time is 1-1.5 h. In this condition, in the same sample, the glycerol spectrophotometry obtained the content of konjac glucomannan is 73.44%, the returns-ratio was 98. 6 %, the accuracy was 0.98. The phenol spectrophotometry obtained content of konjac glucomannan is 70.87%, the returns-ratio was 102.7%, the accuracy was 0.93. The result indicated, this method （DNS I ） has the conveniently, security,low cost and so on the merit,suits to the common laboratories for quantitative analysis.