小麦纤维对小麦淀粉热力学及流变学特性的影响研究

Research on Effect of Wheat Fiber on Thermodynamic and Rheological Properties of Wheat Starch

利用快速黏度分析仪(RVA)、差示扫描量热仪(DSC)、流变仪(DHR)和扫描电镜(SEM)测定添加小麦纤维对小麦淀粉糊化特性、热力学特性、流变学特性和微观结构的影响。结果表明,随小麦纤维添加量的增加,小麦淀粉崩解值和回生值显著降低,表明小麦纤维抑制了小麦淀粉凝胶的老化;在4℃环境下储藏7d后,其老化焓值随小麦纤维添加量增加显著降低,抗老化性显著提升;添加不同浓度小麦纤维的淀粉糊为假塑性流体,小麦淀粉凝胶均为弱凝胶;小麦淀粉凝胶微观结构显示小麦纤维添加使小麦淀粉凝胶的表面更加完整、结构更加致密。由此表明小麦纤维对小麦淀粉凝胶老化有显著抑制作用。

The effect of adding wheat fiber on wheat pasting characteristic, thermodynamic and rheological was investigated by means of rapid viscosity analyzer(RVA), differential scanning calorimetry(DSC), rotational rheometer and scanning electronic microscope(SEM). RVA results showed that the adding of wheat fiber significantly decreased the breakdown and setback values, which meant that the retro-gradation of wheat starch was inhibited. After stored at 4 ℃ for 7 days, DSC curves showed clearly that wheat fiber significantly reduced the retro-gradation enthalpy of amylopectin, aging resistance improving significantly;adding wheat fiber of starch paste of different concentration as the pseudo plastic fluid;the wheat starch gel was all weak gel;the;the wheat starch gel micro structure showed that the adding of wheat fiber made the surface of the gel more complete, and the structure more cohesive,from which it could be concluded that the adding of wheat fiber apparently inhibited the retro-gradation of wheat starch.