本文研究了动态高压微射流（DHPM）处理对薜荔籽低酯果胶物化性质及其结构的影响。采用不同压力（0~160 MPa）和次数（1~9次）对其进行处理，以分子量、特性粘度、粒径、还原糖含量、红外光谱、表观形貌等为评价指标，综合分析了DHPM处理对其分子结构和物化性质的影响。研究结果表明：随着DHMP处理压力和次数的增加，低酯果胶的特性粘度，分子量及粒径降低，还原糖含量升高，同时低酯果胶表观形貌由片状结构向丝状结构转变，表明低酯果胶在DHMP处理过程中发生了降解，其降解主要原因是DHMP机械力对糖苷键的断裂作用。经处理果胶和未处理果胶的红外图谱基本相似，但是在1744.8 cm-1处的C=O的吸收峰随着处理压力的增加而增大。甲氧基和双键含量测定实验表明DHPM处理不会导致低酯果胶发生去甲酯化和β-消除反应。

In this study, the effects of dynamic high-pressure microfluidization (DHPM) on the physicochemical properties and structure of low-methoxyl pectin (LMP) from Ficus pumila L. seeds were studied. LMP was treated under different DHPM pressures (0~160 MPa) and cycles (1~9 times), and the structure and physicochemical properties of DHPM-treated LMP were comprehensively evaluated using various indicators such as molecular weight, intrinsic viscosity, particle size, reducing sugar level, Fourier transform infrared (FT-IR) spectra, and surface morphology. The results showed that with increasing DHPM pressures and cycles, the molecular weight, intrinsic viscosity, and particle size of LMP decreased, whereas the amount of reducing sugars increased. At the same time, the surface topography of LMP changed from a foliated structure to a filament structure, indicating that LMP degraded during DHPM. The degradation of LMP mainly resulted from the rupture of the glycosidic bond by DHPM mechanical forces. The FT-IR spectra of DHPM-treated pectin had features similar to those of untreated pectin; however, the intensity of the absorption peak at 1744.8 cm-1 (C=O) increased with increasing DHPM pressures. The experimental determination of the methoxyl group and double bond contents revealed that demethoxylation and β-elimination did not occur during DHPM.

国家自然科学基金资助项目（31260386）；江西省科技支撑计划（20121BBF60039）