辅助降血糖保健食品水溶性多糖测定方法的研究

摘要

建立一种辅助降血糖保健食品中水溶性多糖的测定方法，考察提取方式、醇沉浓度、脱蛋白方法及显色方法等因素对多糖测定结果的影响。结果表明选用苯酚硫酸法进行显色，超声提取60 min，超声功率250 W，醇沉浓度80％，以样液体积1／10倍量的5％三氯乙酸溶液，脱蛋白1次，静置时间2 h，测定结果较好。葡萄糖浓度在6.61～79.28μg／mL 范围内与吸光度有良好的线性关系，回归方程为 A ＝0.0144C －0.0655（r ＝0.9996），平均加标回收率为98.47％，RSD 为1.64％。测得样品中水溶性多糖平均含量为11.49％，RSD 为2.31％。该方法简便、准确，重复性好，可用于辅助降血糖保健食品中多糖含量的测定和质量控制。%To establish a method for determination of the content of water - soluble polysaccharides in auxiliary hypoglycemic health food,the effects of extraction method,concentration of ethanol for precipi-tation,deproteinization method and coloration method on the determined values of polysaccharides content were studied.Result showed that the phenol -sulfuric acid method was chosen as the coloration method, with the conditions as follows:ultrasonic power 250 W,extraction time 60 min,80% ethanol concentra-tion for precipitation,and 1 /10 polysaccharide extraction volume,5% trichloroacetic acid concentration for deproteinization,deproteinization once,standing time 2 h,and the result was good.The standard curve regression equation was A =0.0144C -0.0655,the calibration curve had a good linearity in the range of 6.61 -79.28 μg/mL for glucose with the correlation coefficient (r)of 0.9996,and the average recovery at the spiked concentrations was 98.47% with RSD of 1.64%.The average content of water -soluble polysaccharides from the auxiliary hypoglycemic health food was 11.49% with RSD of 2.31%. This method was simple and accurate with a good repetion,which can be used to determine the content of polysaccharides in auxiliary hypoglycemic health products.