本研究将鲢鱼鳞胶原肽与亚铁离子进行螯合，以螯合率为评价指标，通过单因素实验结合响应面分析法，探究胶原肽-铁螯合物的最佳制备条件并对其分子量分布、氨基酸组成和结构进行表征。结果表明：胶原肽-铁螯合物的最佳制备条件为pH 7.5、肽铁质量比5：1、肽液浓度2.5%、螯合时间30min、螯合温度35℃，在此条件下，铁的螯合率为92.04%。由分子量分布和氨基酸组成分析可知，胶原肽与Fe2+螯后1000 u以下的分子量占比下降，胶原肽中存在的谷氨酸、天冬氨酸、丙氨酸、缬氨酸和精氨酸对螯合反应具有重要作用；紫外和红外光谱结果表明，胶原肽中的羧基、氨基和酰胺基等基团参与了螯合反应；X射线衍射图谱也显示鲢鱼鳞胶原肽-铁螯合物呈现出不同于胶原肽的非晶形结构。本研究可望为鲢鱼鳞胶原肽-铁螯合物的制备、工艺优选及结构表征提供参考。

In this work, the optimal preparation conditions of silver carp scale collagen peptide-ferrous iron chelate were obtained by single factor experiment combined with response surface methodology using the chelation rate as the evaluation index. In addition, the structure of collagen peptide-iron chelate prepared with the optimal conditions was detected. The results indicated that the optimal preparation conditions of collagen-iron chelate were as follows: the pH of the reaction was 7.5, the mass ratio of the polypeptide to ferric salt of the reaction was 5:1, the concentration of peptide of the reaction was 2.5%, chelating time of the reaction was 30 min, chelating temperature of the reaction was 35℃. Under these conditions, the chelating rate of iron was 92.04%. According to the molecular weight distribution and amino acid composition analysis, after collagen peptide and Fe2+, the proportion of molecular weight below 1000 u decreased, and glycine, glutamic acid, aspartic acid and arginine in collagen peptides play an important role in the chelating reaction. Simultaneously, the results of Uv-vis and FTIR spectra demonstrated that the carboxyl group, amino group and amino group on the amide bond of collagen peptide were involved in the chelation reaction. Furthermore, a different amorphous structure was observed in silver carp scale collagen peptide-iron chelate compared to collagen peptide by X-ray diffraction. This study is expected to provide a reference for the preparation, optimization and structural characterization of silver carp collagen peptide-iron chelate.

高蛋白桑树草本化栽培及桑叶肽产品研发关键技术研究与示范；中央高校基本科研业务费专项基金资助