研究将淀粉的酯化改性在高静压的协同作用下进行。选择木薯淀粉为原料，压力水平300、450及600 MPa，以醋酸酐为酯化剂，合成高静压酯化木薯淀粉。借助偏光显微镜、傅里叶红外光谱仪、粘度计、可见光分光光度计等分析手段，对其结构及理化性质进行系统研究。结果表明，红外光谱显示在1700 cm-1左右形成酯键，随着压力的升高偏光十字并没有明显的变化，说明形成的酯键使淀粉颗粒的晶体结构更加稳定，即使在600 MPa的高压下，淀粉颗粒的结构也不会明显的破裂。高静压协同酯化木薯淀粉的稳定性降低，抗酸性增强，变性淀粉相对原木薯淀粉而言抗老化性明显。450 MPa较300、600 MPa压力水平的冷、热粘度差值最大，其差值为27.56 mPa?s。以上说明变性淀粉可以在造纸、纺织和化工等领域拥有更广阔的应用前景。

The modification of starch by the high hydrostatic pressure (HHP)-assisted esterification reaction was studied herein. Tapioca was selected as the raw material and the esterified tapioca samples were synthesized using HHP-assisted reactions with acetic anhydride at 300, 450, and 600 MPa. The physicochemical and structural properties were systematically studied via a polarized light microscope, Fourier transform infrared (FT-IR) spectrometer, viscometer, visible spectrophotometer, and others. The FT-IR spectra showed an absorbance peak attributable to the ester group at approximately 1700 cm-1 and no significant changes in the birefringence were observed with increasing pressure. This demonstrated that the crystal structure of the starch granules was markedly stabilized by the formed ester linkage, and no apparent ruptures occurred in starch granules even at the high-pressure treatment of 600 MPa. The HHP-assisted esterified tapioca starch showed reduced stability, enhanced acid resistance, and obvious aging resistance compared with the original tapioca. The esterified tapioca prepared at 450 MPa exhibited the largest difference (27.56 mPa?s) between cold and hot viscosities compared with those prepared at 300 and 600 MPa. The above results demonstrated that the modified starch has broad prospects for application in papermaking, textile, and chemical industries.

国家自然科学基金资助项目（21006043）