米糠多糖的提取及其含量的测定

Extraction and Determination of the Polysaccharides in Rice Bran

对米糠中的多糖进行提取与测定,采用水提醇沉法对米糠中的多糖进行提取,并采用苯酚—硫酸法测定其多糖含量,以正交实验优化显色条件。确定检测波长为490nm,确定6%苯酚用量为1.0mL,浓硫酸用量7.5mL,反应时间为30min。在(0.0025—0.030)mg/mL范围内,呈良好的线性关系。平均回收率为97.8%,RSD=3.89%(n=6)。测得米糠粗多糖含量为20.2%。结果表明方法简单、准确,为继续研究开发提供一定的参考依据。

The polysaccharides in rice bran was separated and purified with water extracting and ethanol depositing,and the content was determined by phenol-sulfuric acid method.The main factors affected the method were optimized.The optimum determination wavelength was 490 nm,the reaction time was 30 min,and dosage of 6% phenol and sulfuric acid was 1.0 mL and 7.5 mL,respectively.From the range of （0.002 5—0.030） mg/mL,there was an excellent linear shape between the concentration and absorptance.The average recovery was 97.8%,RSD was 3.89%.The content of polysaccharides was 20.2%.The method is simple and accurate.