苯酚-硫酸显色法测定生菜中的多糖含量

采用苯酚-硫酸显色法测定了生菜中多糖的含量,讨论了反应温度、反应时间、测定波长、苯酚及硫酸的用量等因素对显色反应的影响.在优化条件下,用分光光度法测量其吸光度.根据标准曲线回归方程A=9.770 51C+0.003 3(r=0.998 6)求出多糖含量.结果表明,生菜中多糖的含量为70.21 mg/g,平均回收率为98.0%,相对标准偏差RSD为1.16%,准确度高.该法可为蔬菜中多糖含量的测定提供一种快速简便的技术.

Determination of Polysaccharide Content in Lettuce by Phenol-sulfuric Acid Chromogenic Method

In this paper,the polysaccharide content in the lettuce was determined by the phenol-sulfuric acid chromogenic method,reaction temperature,reaction time,the detection wavelength,the dosage of phenol and sulphuric acid was discussed.Under the optimal conditions,absorbance was measured by spectrophotometry.The polysac-charide content was read out according to standard curve regression equation A=9.770 51C＋0.003 3（r=0.998 63）. The results showed that the polysaccharide content in the lettuce was 70.21 mg/g,the averaged recovery was 98.0%, the relative standard deviation RSD was 1.16%and the accuracy was high.This method provided a quick and con-venient technique for the determination of the polysaccharide content in the vegetables.