Abstract:

The preparation procedure of Zn (Ⅱ)–tilapia peptide complexes was investigated by single factor design method. Along with this, the complexes were structurally characterized and their biological activities were tested by measuring their effects on kidney GSH-Px and hepatic SOD activities and the percentage of macrophages engaged in phagocytosis in mice and in vitro superoxide anion free radical scavenging activity. Results showed that the optimal reaction conditions for the preparation of Zn (Ⅱ)–tilapia peptide complexes were as follows: pH 5.0 and 80 ℃ for a reaction between Zn (Ⅱ) and tilapia peptides contained in the tilapia meat hydrolysate with 15% degree of hydrolysis. Under such conditions, the yield of Zn (Ⅱ)–tilapia peptide complexes with a Zn content of 6.5 × 104 mg/kg reached up to 54% and Zn exhibited a chelation rate of 55%. Spectral characteristics demonstrated the formation of new complexes from Zn (Ⅱ) and tilapia peptides. The complexes remarkably increased the percentage of macrophages engaged in phagocytosis and hepatic SOD and kidney GSH-Px in mice and exhibited an excellent superoxide anion free radical scavenging activity.

Key words: tilapia, Zn (Ⅱ)&ndash, tilapia peptide complexes, preparation, biological activity