3种改性方法对小麦麸皮膳食纤维结构与性质的影响

Effects of Three Modification Methods on the Structure and Characters of Wheat Bran Dietary Fiber

为获得具有良好功能性质的小麦麸皮膳食纤维,分别对挤压膨化改性、纤维素酶解改性和挤压-酶法改性的小麦麸皮膳食纤维的结构及性质进行测定与比较分析。研究结果表明:3种改性方法都可改变膳食纤维的微观结构,挤压改性的膳食纤维呈块状,酶解改性膳食纤维表面凹凸不平,而挤压-酶解改性膳食纤维表面出现孔状结构;改性后膳食纤维的持水力、膨胀力、溶解性和黏度以及对脂肪、胆固醇、亚硝酸根离子的吸附能力都相应提高,且挤压-酶解改性后各物性指标更优于挤压改性和酶解改性。因此,挤压-酶解法是一种较好的小麦麸皮膳食纤维的改性方法。

In order to acquire good functional properties of wheat bran dietary, the structure and properties of wheat bran dietary were measured and analyzed comparatively after wheat bran dietary were modificated by extru- sion, cellulose enzyme hydrolysis and extrusion -enzymatic methods, respectively. The results showed that the micro- structures of dietary fiber were all changed by the three modification methods. The dietary fiber modified by extrusing displayed schistose structure. The surface of dietary fiber modified by enzyme became uneven, and there were some hole structures with certain depth on the surface of dietary fiber modified by extrusion -enzyme coaction. Moreover, after modification, the dietary fiber properties including water holding capacity, swelling power, solubility and viscosi- ty of were increased to some extent, and as well as its adsorptivity to fat, cholesterol, nitrite ion. And in addition, ex- trusion - enzymatic modification testified about more significantly effects on the all physical properties than the other two modification methods mentioned in present paper. Therefore, extrusion -enzymatic hydrolysis method was proved to be one of the better modification method of wheat bran dietary fiber.