微波改性对小麦麸皮膳食纤维结构和理化性质的影响

Effects of Microwave Modification on the Structure and Physicochemical Properties of Wheat Bran Dietary Fiber

以小麦麸皮为原料,利用微波对麦麸膳食纤维(Wheat bran dietary fiber,WBDF)进行改性处理,通过扫描电镜、X-衍射和傅里叶变换红外光谱研究改性前后膳食纤维结构的变化。在此基础上,对改性前后WBDF的持水力、水膨胀力、持油力等理化性质进行了比较。扫描电镜结果显示,改性WBDF表面呈现复杂的网状结构,空隙增多,比表面积增大,可及性边缘增多。X-衍射结果显示,改性WBDF晶体形态未发生改变。红外光谱显示,改性前后WBDF的特征吸收峰的整体峰型、位置并未发生明显改变,仅强度有所增强。理化性质结果显示,改性WBDF在持水力、水膨胀力和持油力方面明显优于对照组。持水力在微波功率为600 W时达到最大,为8.07 g/g,比对照组提高71.7%;改性前后水膨胀力的变化较小,在微波功率为450 W时达到最大,为1.68 mL/g,比对照组提高15.9%;持油力在微波功率为450 W时达到最大,为7.33 g/g,比对照组提高74.5%。

The structure and the physicochemical properties of wheat bran dietary fiber(WBDF)by microwave treatment were investigated.Scanning electron microscopy(SEM)showed that the surface of modified WBDF exhibited complex network structure with more voids,larger specific surface area and more accessible edges.X-ray diffraction(XRD)results showed that the crystal morphology of modified WBDF was not changed.Fourier transform infrared spectroscopy(FTIR)results showed that microwave treatment did not change the overall peak pattern and position of the characteristic absorption peaks of WBDF significantly,but the intensity of the absorption peak was increased.The results of physicochemical properties showed that the modified WBDF was significantly better than the control in terms of waterholding capacity,water-swelling capacity and oil-holding capacity.The maximum water-holding power of 8.07 g/g was obtained at the microwave power of 600 W,which was 71.7%higher than that of the control;The change of water-swelling capacity before and after modification was small,reaching the maximum value of 1.68 mL/g at the microwave power of 450 W,which was 15.9%higher than that of the control;The maximum oil-holding capacity was 7.33 g/g when the microwave power was 450 W,which was 74.5%higher than the control.