Abstract:

In order to achieve value-added utilization of byproducts of freshwater fish processing and simultaneously reduce
environmental pollution and resource waste, silver carp bone was used as the raw material to prepare calcium-chelating
collagen polypeptides. Under given conditions, calcium binding capacity and chelated calcium content were investigated
as a function of reaction temperature, mass ratio between bone collagen polypeptides and calcium chloride (P/C), time
and pH. On the basis of the results of single-factor experiments, the four reaction parameters were optimized by a fourfactor
quadratic orthogonal rotational combination design to be 42 ℃, 38 min, a P/C ratio of 2.1:1 and pH 6.8, yielding a
calcium binding capacity of 80.4% and a chelated calcium content of 12.1%. Amino acid composition analysis showed that
the calcium-chelating collagen polypeptides obtained contained 61.03% amino acids in total and had typical amino acid
composition characteristics. Infrared spectroscopic analysis and scanning electron microscopy observation confirmed the
chelating reaction between calcium ion and collagen polypeptides by ionic bonding, coordination or adsorption.

Key words: fish bone, collagen peptide, chelated calcium