高静压处理对红薯淀粉颗粒结构的影响

淀粉颗粒结构研究是进行淀粉改性及拓宽其应用范围的基础。采用高静压对红薯淀粉进行改性处理，并 通过扫描电子显微镜观察、X射线衍射分析、傅里叶变换红外光谱分析、差示扫描量热分析及快速黏度分析探究不 同压力对淀粉颗粒结构的影响。结果显示，200～500 MPa高静压处理的红薯淀粉颗粒形貌无明显变化。600 MPa 处理后，淀粉颗粒开始塌陷并与周围颗粒凝聚，失去双折射现象；峰值黏度、谷值黏度和最终黏度分别显著升高 9.15%、27.18%和20.21%（P＜0.05）；糊化温度升高1.9 ℃，峰值时间延长1.16 min，但糊化焓和崩解值分别显著 降低46.18%和66.46%（P＜0.05）。此外，高静压处理后红薯淀粉分子基团和晶体类型保持不变。

Effect of High Hydrostatic Pressure on Granular Structure of Sweet Potato Starch

Studying starch granular structure is the basis for starch modification and extended scope of application. In the present work, the effect of high hydrostatic pressure (HHP) treatment on the granular structure of sweet potato starch was investigated by scanning electron microscope, X-ray diffraction, differential scanning calorimetry, Fourier infrared transform spectroscopy and rapid visco analysis. The results showed that surface morphology of starch granules was not significant changed after treatment at 200–500 MPa. When the pressure increased up to 600 MPa, the starch granules began to collapse and coagulate, thereby losing birefringences; the peak viscosity, trough viscosity and final viscosity were enhanced by 9.15%, 27.18% and 20.21% (P < 0.05), respectively; and the pasting temperature and peak time were increased by 1.9 ℃ and 1.16 min, while the pasting enthalpy and breakdown viscosity were decreased by 46.18% and 66.46% (P < 0.05). In addition, the crystal type and molecular groups of sweet potato starch remained unchanged after HHP treatment.