羧甲基大豆膳食纤维的制备及性能

Preparation and Properties of Carboxymethyl Soybean Dietary Fiber

以大豆膳食纤维为原料，一氯乙酸（MCA）为醚化剂，异丙醇为溶剂，制备了羧甲基大豆膳食纤维，研究了异丙醇溶液质量分数、NaOH用量、MCA用量、碱化时间、醚化温度、醚化时间对产品羧甲基质量分数的影响。实验得出较佳反应条件为：异丙醇溶液质量分数95％，m（NaOH）：m（DF）：m（MCA）=1、00：1．25：1．20，碱化时间60min，醚化温度70℃，醚化时间120-150min，所得产品羧甲基质量分数为3．85％，水溶性膳食纤维（SDF）质量分数为71．07％。大豆膳食纤维经羧甲基化后，水溶性膳食纤维质量分数、溶液黏度和透明度显著提高；并且随羧甲基质量分数的增加，SDF质量分数增大，溶液黏度和透明度提高。

The carboxymethyl soybean dietary fiber was prepared by using soybean dietary fiber as raw material, monochloracetic acid as etherification reagent and isopropanol as solvent. The effects of isopropanol solution mass concentration, amount of sodium hydroxide, amount of monochloracetic acid, alkalization time, etherification temperature and etherification time on the carboxymethyl content were investigated. The optimal conditions were obtained that isopropanol concentration 95%, mass ratio of sodium hydroxide to soybean dietary fiber and monochloracetic acid 1.00： 1.25： 1.20, alkalization time 60 minutes, etherification temperature 70 degrees C, and etherification time 120 - 150 minutes. The carboxymethyl content and soluble dietary fiber content of carboxymethyl soybean dietary fiber prepared under the optimal conditions are 3.85% and 71.07%, respectively. The soluble dietary fiber content, solution viscosity and transparency are improved obviously after soybean dietary fiber being carboxvmethvlated, and increase with inereasing carboxymethyl content.