表没食子儿茶素没食子酸酯与燕麦β-葡聚糖复合物的形成及表征

多酚与膳食纤维间可通过相互作用形成复合物，为了探究多酚与膳食纤维间的相互作用机制及其所形成复合物的结构和形态，本文选用表没食子酸儿茶素没食子酸酯（Epigallocatechin gallate，EGCG）和燕麦β-葡聚糖为原料制备复合物并对其结构进行表征。结果表明:EGCG与燕麦β-葡聚糖复合物的形成与EGCG浓度和pH有关，EGCG与燕麦β-葡聚糖在质量比为0.8:1，pH5的水溶液中可形成粒径为1.7 μm，颗粒相对均一（分散系数为0.38）的复合物；通过透射电镜观察到EGCG与燕麦β-葡聚糖间形成了形貌规整的球状颗粒；等温量热滴定（ITC）分析用于表征EGCG-燕麦β-葡聚糖复合物在pH5和25 °C下的相互作用机制，发现EGCG和燕麦β-葡聚糖之间的结合主要是非共价相互作用中的氢键和疏水相互作用。综上可知，EGCG与燕麦β-葡聚糖能够自发地通过非共价相互作用形成复合物，本研究结果可为不同多酚-燕麦β-葡聚糖复合物作为功能性食品成分或生物活性材料的应用提供理论参考和研究依据。

Formation and Characterization of the Complex of Epigallocatechin Gallate and Oat β-Glucan

Polyphenols and dietary fiber can form complexes through their interactions. In order to investigate the interaction mechanism between polyphenols and dietary fibers, and the structure and morphology of complexes formed by them, this paper selected epigallocatechin gallate and oat β-glucan as the raw materials for the preparation of the complexes and their structural characterization. The results indicated that the formation of the complex of EGCG and oat β-glucan was related to the concentration and pH of EGCG, EGCG and oat β-glucan could form a complex with a particle size of 1.7 μm and a relatively uniform particle size (dispersion coefficient 0.38) in an aqueous solution with a mass ratio of 0.8:1 and pH5. Through transmission electron microscopy, the formation of regular spherical particles between EGCG and BG were clearly observed. Isothermal Titration Calorimetry (ITC) measurement was used to characterize the EGCG-BG complex. The binding mechanism at 25 °C clearly provided that the binding between EGCG and BG were mainly non-covalent interaction (such as hydrogen bonding and hydrophobic interaction). The above experimental results could indicate that EGCG and BG could spontaneously form a complex through non-covalent interactions. In summary, the findings of this study would provide a theoretical reference and research basis for the use of different polyphenol-oat β-glucan complexes as functional food ingredients or as bioactive materials.