超声场中马铃薯淀粉糊的特性粘度变化及其机理

为深入了解超声场中马铃薯淀粉糊特性粘度的变化规律,通过乌氏粘度计测定淀粉特性粘度的变化,使用傅立叶红外光谱分析(FT-IR)结合紫外可见分分光光度计分析,表征超声处理后的马铃薯淀粉糊的性质。结果表明,马铃薯淀粉糊特性粘度随作用时间的延长而降低,随超声声强的增大而减少;超声场对马铃薯稀淀粉糊的影响更大,马铃薯淀粉糊的浓度越小,特性粘度下降程度越大,超声场作用后马铃薯淀粉糊的特性粘度越小;马铃薯淀粉糊特性粘度随超声作用时间的延长而降低。傅立叶红外光谱分析表明,组成淀粉分子的单体α-D-吡喃葡萄糖在超声场中没有明显改变。超声场作用后,马铃薯淀粉糊的直链淀粉含量增大,结合键能大小分析,推断出超声场作用马铃薯淀粉糊的断链位置可能发生在糖苷键C-O上。超声作用使得马铃薯淀粉分子链发生断裂,马铃薯淀粉糊特性粘度降低。

Change of Intrinsic Viscosity of Potato Starch Paste in Ultrasonic Field and Its Mechanism

In order to understand the change of intrinsic viscosity of potato starch in ultrasonic field and its mechanism,the change of intrinsic viscosity of starch was measured by Ubbelohde viscometer. Fourier transform infrared spectroscopy(FT-IR)combined with UV-Vis spectrophotometer was used to characterize the properties of potato starch paste after ultrasonic treatment. The results showed that,the intrinsic viscosity of potato starch paste decreased with the extension of ultrasonic time the increase of ultrasonic intensity;the influence of ultrasonic field on diluted starch paste was greater;the lower the concentration of potato starch paste,the greater the decrease of intrinsic viscosity,and the smaller the intrinsic viscosity of potato starch paste. Fourier transform infrared spectroscopy showed that the structural units α-D-glucosamine that made up the starch molecule did not change significantly in the ultrasound field. After ultrasonic treatment,the amylose content of potato starch paste increased,and the size of bond energy was analyzed. It was deduced that the position of chain scission of potato starch paste in ultrasonic field might occur on the glycosidic bond C-O. Ultrasound caused breakage of the potato starch molecular chains,and the intrinsic viscosity of the potato starch paste was reduced.