麦麸水不溶性膳食纤维对NO_2^-清除作用的研究

麦麸水不溶性膳食纤维在胃液pH值条件下对NO2-具有强烈的清除作用。其最大清除速率（Vmax）为10.52μmol／g·h，最小清除浓度（Cmin）为0.68mol／L，最大清除量（Mmax）为35.65mol／g。随着pH升高，清除能力急剧下降。低pH下被清除的NO2-王在pH7时会有少量重新释放出来。金属离子Ca2+、Fe2+、Zn2+对其清除NO2-有促进作用，同时能阻止pH升高后NO2-的再释放。

Under the condition of pH similar to stomach's, the water-insouble dietary fiber (IDF) from wheat (Triticum aetheum L. )bran had high scavenging ability for nitrite. It scavenged NO2- at 36. 65 μmol per gram and reduced NO-2 at a maxium rate (Vmax) of 10. 52μmol/g/h to a minimum concenfration (Cmin),0. 68μmol/L. Its NO2- scavenging capacity decreased sharply as pH increased. A small part of NO2- bound to IDF at low pH released when pH increased to 7. The metal irons such as calclum, iron and Zinc had synergistic effect on IDF. At pH 2, 2. 5mg/ml CaCl2, 30μg/ml FeSO4. 7H2O and 30μg/ml ZnSO4.7H2O increased the amount of scavenged nitrite by 47. 0%, 29. 5% and 29. 1% respectively, and also effectively prevented the release of NO2 after pH was raised to 7.