超高压处理对变温结晶制备糯米慢消化淀粉的影响

以糯米粉（蛋白质量分数为7.97%）和糯米淀粉（蛋白质量分数为0.58%）为研究对象，利用超高压（100、300、500?MPa）结合变温结晶（4?℃和25?℃间隔24?h循环条件下放置1、3、7?d）的方式制备慢消化淀粉，通过测定样品的慢消化淀粉质量分数并进行热力学性质、糊化特性和傅里叶变换红外光谱分析，研究超高压处理对变温结晶制备糯米慢消化淀粉的影响。结果表明，糯米淀粉所制得的慢消化淀粉含量大于糯米粉。糯米淀粉在超高压压强500?MPa下放置7?d，慢消化淀粉质量分数最高，可达30.32%。差示扫描量热分析结果表明，经变温结晶后的样品焓变增加；快速黏度分析结果表明，随着超高压压强的增加，糯米淀粉组回生值和最终黏度降低，慢消化淀粉含量增加；傅里叶变换红外光谱结果表明，在相同处理条件下，与糯米粉组相比，糯米淀粉组的短程有序结构比例更高。本研究可为制备具有健康功效的慢消化淀粉提供新的思路。?

Effects of Ultra-high Pressure Treatment on the Preparation of Slowly Digestible Starch from Glutinous Rice by Temperature-Cycled Retrogradation

Slowly digestible starch (SDS) was prepared separately from glutinous rice flour (with 7.97% protein) and glutinous rice starch (with 0.58% protein) by ultra-high pressure (100, 300 and 500 MPa) combined with temperature-cycled retrogradation (holding at alternating temperatures of 4 and 25 ℃ for 1, 3 and 7 days with 24 h intervals). The influence of ultra-high pressure (UHP) treatment on the purity, thermal properties, gelatinization properties and Fourier transform infrared (FTIR) spectrum of SDS was evaluated. The experimental results showed that the purity of SDS prepared from glutinous rice starch was higher than that prepared from glutinous rice flour. After 7 days of temperature-cycled retrogradation, the purity of SDS prepared from glutinous rice starch with UHP treatment at 500 MPa reached a maximum level of 30.32%. The differential scanning calorimetric (DSC) experiments showed that the enthalpy change of the SDS samples increases after temperature-cycled crystallization. The rapid viscoanalyzer (RVA) experiments demonstrated that the retrogradation value and final viscosity of SDS from glutinous rice starch decreased and the purity increased with increasing pressure. The FTIR spectra illustrated that the proportion of short-range ordered structure in SDS from glutinous rice starch was higher than that from glutinous rice flour.