欧李果胶理化特性及乳化性质

以商品苹果果胶（commercial apple pectin，CAP）为对照，研究欧李果胶（Cerasus humilis fruit pectin，CSP）的结构、理化性质及乳化特性。与CAP对比，所得CSP半乳糖醛酸质量分数为70.42%，含有更高含量的金属元素（Ca、Zn、Mg）、蛋白质和总多酚（P＜0.05）。通过扫描电镜、傅里叶变换红外光谱、气相色谱-质谱联用、X射线衍射等结构表征表明，CSP表面呈光滑、连续和卷曲的片状或丝状结构，为高甲氧基果胶（酯化度52.04%），具有无定形性质，阿拉伯糖（65.7%）、半乳糖（18%）和鼠李糖（11%）为其主要的3 种中性单糖。此外，通过测定CSP的Zeta电位值和其乳液体系的乳化指数、乳化能力、乳化稳定性、显微结构、液滴粒径及流变学性质，探究CSP的乳化性质。结果显示，CSP具有较好的乳化性质，可作为乳液体系的天然乳化剂，具有巨大潜力。

Physicochemical Characterization and Emulsification Properties of Cerasus humilis Fruit Pectin

The structure, physicochemical properties and emulsifying properties of Cerasus humilis fruit pectin (CSP) were studied. Compared with commercial apple pectin (CAP), the content of galacturonic acid (GalA) in CSP was lower, while the contents of some metal elements (Ca, Zn and Mg), protein and total polyphenols were significantly higher (P < 0.05). Structural characterization by scanning electronic microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, gas chromatography (GC-MS) and X-ray diffraction (XRD), demonstrated that CSP showed a smooth surface with continuous and curly lamellar or filamentous structure. It was a high methoxy pectin with degree of esterification (DE) of 52.04% and was amorphous Arabinose (65.7%), galactose (18%) and rhamnose (11%) were the major three neutral monosaccharides in CSP. Moreover, the emulsifying properties of CSP were determined by measuring its zeta potential value and the emulsification index (CI), emulsification capacity (EC), emulsion stability (ES), microstructure, droplet size and rheological properties of an emulsion system stabilized by it. Our results show that CSP has good emulsifying properties and thus has great potential to be used as a natural emulsifier.