Abstract:In this study, the preparation process and structural characteristics of the short peptides chelated ferrous ions from channa argus were investigated. The short peptides were obtained from channa argus protein by trypsin hydrolysis. Single factor and response surface analyses were applied to optimize the preparation of higher chelating rate short peptides chelated ferrous ions from channa argus. Its structure was analyzed by means of amino acid analysis, spectral scanning and electron microscopy. The optimal chelating conditions were listed as follow: enzyme dosage of 35000 U/g, pH of 6.0, peptides/iron chloride of 3:1 (m/m), chelating temperature of 25 ℃, chelating time of 30 mins. The value of the highest chelating rate was 84.46 % at this condition. The amino composition analysis of the short peptides showed that the content of aspartic acid and glutamic acid had significantly increased after chelating reaction, suggesting that acid amino acid had stronger chelating effect on ferrous ions. Ultraviolet-visible (UV-VIS) spectrum, fourier transform-infrared (FT-IR) spectra were obviously polarized and the chelating connection of peptide-iron was formed before and after chelating reaction, suggesting that the amino and carboxyl of the short-peptide were involved in chelating reaction. The microstructure of the short peptides chelated ferrous ions was characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), suggesting that there was an adsorption effect between the short peptide and the ferrous ion, and the structure was close. This study provides some theoretical basis for the high value utilization of the channa argus.
