Abstract:In this study, the calcium-chelating peptide was prepared from eel tail protein by using modern enzymolysis technology. Effects of different single and multiple proteases, enzymolysis time and addition levels of enzyme on protein recovery, peptides yield, calcium chelating ability were systematically evaluated, respectively. The optimal enzymolysis process was obtained as follows: trypsin hydrolysis (3.5‰) was performed at pH 8.0 and 55 ℃for 3 h, and then the pH of the mixture was adjusted to 4.0, followed by acid protease (3.5‰) hydrolysis for 2 h at 55 ℃to obtain eel peptides. The protein recovery and peptides yield were 66.61% and 52.46%, respectively. The effects of chelating temperature, pH value and mass ratios on the calcium chelating ability of eel peptides were investigated. The chelating conditions of calcium-chelating peptides were optimized as follows: 30 ℃, pH 9.0, the mass ratio of eel peptides to calcium 1:2 and chelating with calcium for 30 mins. The calcium content of calcium-chelating peptides was 56.78 mg/g. In addition, glutamic acid and aspartic acid were found to be a great contribution to chelating reaction between eel peptides and calcium via the amino acid composition analysis.
