Iron-chelating activity of large yellow croaker (Pseudosciaena crocea) roe hydrolysates

In this study, hydrolysates of large yellow croaker (Pseudosciaena crocea) roe were prepared by trypsin (Try-pcRHs) and papain (Pap-pcRHs). The degree of hydrolysis (DH), molecular weight distribution and iron chelating capacity of hydrolysates were investigated. Moreover, the chelation mechanism of iron-hydrolysates complex also was investigated by amino acid composition analysis, fourier transform infrared spectrophotometer, fluorescence spectrophotometer and ultraviolet-visible spectroscopy. These results showed that Try-pcRHs exhibited higher iron chelating ability with the EC50 value of 0.14 mg/ml than Pap-pcRHs, which may be due to the higher DH and content of peptide <1 KDa. Furthermore, the Asp, Glu, Ser, Pro, Ile, Phe and His in Try-pcRHs might contribute to the chelation reaction, and the groups of -COOH, C=O, N-H and C-O were involved in chealtiong of Try-pcRHs with iron. Therefore, Try-pcRHs have the potential to be used as iron supplements in food industries. Practical Applications Large yellow croaker (Pseudosciaena crocea) roes are the main by-products in the large yellow croaker processing. Previous studies have found that protein isolates from P. crocea roes composed of vitellogenin B, vitellogenin C and vitellogenin contain a large number of serine residues. In this study, we prepared hydrolysates from large yellow croaker roes, and the results showed that trypsin-hydrolyzed large yellow croaker roes exhibited great iron-chelating ability and has the potential to be used as a safe and healthy iron supplements in the food industry.