The glucomanna in disposed Amorphophallus konjac was extracted with water and precipitated with ethanol after removal of its impurities by steeping with 50% ethanol at room temperature.

• 处理过的鲜花魔芋样品经50%25乙醇浸泡除杂,水提醇沉,以葡萄糖为标准品,用苯酚-硫酸比色法测定其中葡甘聚糖的含量。