Preparation and antioxidant properties of tilapia (OREOCHROMIS NILOTICUS) protein hydrolysates-copper complex

摘要

Tilapia protein hydrolysates (TPH) were obtained by enzymatic hydrolysis of tilapia meat using papain, and then the TPH binded with copper at various mass ratios of TPH to CuCl_2 (5:1, 10:1 and 20:1) to obtain complex I, complex II and complex III, respectively. The copper-binding rate, antioxidant properties, and FTIR spectrum of the complex were investigated. It was found that the copper-binding rate increased with the increase of mass ratios (TPH/CuCl_2) from 5:1 to 20:1. The DPPH radical scavenging activity and reducing power activity of TPH were higher than that of the complexes. However, the lipid peroxidation inhibition activity was improved after TPH binded with copper. It was also found that the antioxidant activities of complex III were highest in the complexes. FTIR spectra demonstrated that some sites such as amino nitrogen atoms in TPH could bind with copper to form the complex.