该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值7.5、肽铁质量比5:1、肽液质量分数2.5%、螯合时间40 min、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1 000 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。该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。

Silver carp scale collagen peptides were chelated with ferrous ions, with the chelation rate as an evaluation index. The optimum preparation conditions for the iron-chelating collagen peptides were explored and their molecular weight distribution, amino acid composition, and structure were characterized via single factor experiments and response surface analysis. The optimal preparation conditions for the iron-chelating collagen peptides were as follows: pH, 7.5; peptide-iron mass ratio, 5:1; peptide solution mass fraction, 2.5%; chelating time, 40 min; and chelating temperature, 35 ℃. Under these conditions, the chelation rate of iron was 92.04%. According to the analysis of molecular weight distribution and amino acid composition, after collagen peptide and Fe2+ chelation, the proportion of molecular weight below 1 000 u decreased, with glutamic acid, aspartic acid, alanine, valine, and arginine in the collagen peptides playing important roles in the chelation reaction. Furthermore, the X-ray diffraction patterns showed that iron-chelating peptides from silver carp scale collagen had an amorphous structure, unlike collagen peptide. This study is expected to serve as a reference for the preparation, optimization, and structural characterization of iron-chelating peptides from silver carp collagen.

湖北省自然科学基金面上项目（2022CFB162）；湖北省重点研发计划项目（2021BBA089）；中央高校基本科研业务费专项基金资助（2662018JC019）