Sustainable and one-pot fabrication of peptide chelated calcium from fish scale hydrolysates

Abstract

Fish scales, considered as low-value by-products, contain peptides and hydroxyapatite that can be applied to produce peptide chelated calcium directly. This study developed a sustainable and one-pot fabrication method for the peptide-chelated calcium from fish scale hydrolysates (FSP-Ca). During pepsin hydrolysis, the releases of peptides (FSP), calcium, and phosphate from fish scales occurred simultaneously, and the chelation was also effectively performed. After a 6-h hydrolysis, the yield of FSP was 46.18%, and the dissolution rate of calcium was 49.53%. Under the optimal conditions (pH 7, chelation time of 25 min, and chelation temperature of 48 °C), a high chelation rate of 86.16% was obtained, with a calcium content of 81.8 mg/g. The results of UV absorption, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the successful chelation between FSP and calcium derived from fish scales. The –NH₂, –COO^–, N–H, C=O, C–H, and –OH groups in FSP participated in the formation of FSP-Ca.

Graphical Abstract

Funding

National Key Research and Development Program of China(2021YFD2100105)

National Natural Science Foundation of China(32372353)

Key Science and Technology Innovation Project of Chongqing Aquatic Science and Technology Innovation Alliance(CQFTIU2022-13)

Fundamental Research Funds for the Central Universities(SWU-XJPY202310)