阿魏酸对小麦淀粉理化特性的影响

以小麦淀粉为原料,分别通过扫描电镜分析、傅里叶红外图谱分析、X-衍射图谱分析、差示扫描量热仪分析及快速黏度测试仪(RVA)分析,研究了添加0、5%、10%、15%、20%(w/w淀粉干基)阿魏酸后小麦淀粉的微观形貌、结晶性质、热力学特性及糊化特性。结果表明:随着阿魏酸含量的增加,淀粉表面不规程度增加,致密性降低;阿魏酸添加量至10%时,T₀(糊化初始温度)、T_P(糊化峰值温度)、T_C(糊化最终温度)和ΔH(糊化焓值)发生显著降低(p<0.05),说明阿魏酸的添加降低了小麦淀粉的稳定性;红外光谱表明,添加阿魏酸后,小麦淀粉在(1045/1022) cm^-1峰强度比值减小,说明添加阿魏酸后小麦淀粉有序性降低;X-衍射图谱表明,糊化后小麦淀粉由原来的A型变为B+V型,并表现出酸的衍射峰明显,说明阿魏酸与小麦淀粉未形成包合物。RVA分析表明,添加阿魏酸降低了小麦淀粉的峰值粘度、保持粘度、最终粘度和回升值降低,而崩解值增大,说明阿魏酸抑制了小麦淀粉的老化进程,扫描电镜分析也证明了阿魏酸抑制了淀粉的老化过程。

Effect of Ferulic Acid on Physicochemical Properties of Wheat Starch

In this study, methods of scanning electron microscope (SEM), fourier infrared spectroscopy, X-ray diffraction spectroscopy, differential scanning calorimeter and rapid viscosity analyzer (RVA) were used to investigate the microstructures, crystallinity, pasting and thermodynamic properties of the wheat flour with adding ferulic acid at a certain level (0, 5%, 10%, 15%, 20%). With the increase of ferulic acid content, the surface irregularity of starch increased and the compactness decreased. When the proportion of ferulic acid reached 10%, the T₀, T_P, T_C and ΔH significantly decreased, indicating that ferulic acid reduced the stability of wheat starch. The peak intensity of (1045/1022) cm-1 decreased with addition of ferulic acid, indicating that the order of wheat starch decreased. After gelatinization, the type of wheat starch changed from A to B+V. X-ray diffraction showed that ferulic acid and wheat starch did not form an inclusion complex. RVA results showed that ferulic acid decreased the peak viscosity of wheat starch, the lowest viscosity, the final viscosity and the setback value, while ferulic acid increased disintegration value. It was indicated that ferulic acid inhibits the aging process of wheat starch. The results of scanning electron microscopy also proved that ferulic acid inhibited the aging process.