Abstract: In order to improve the stability of egg white peptides, high-pressure homogenization-assisted ethanol injection was used to prepare egg white peptide liposomes. The optimum technological conditions were obtained by single factor experiments as follows: cholesterol 2 mg/mL, egg yolk lecithin 10 mg/mL, egg white peptides 50 mg/mL, core-to-wall ratio 3:5, 40 MPa high pressure homogenization for 7 minutes, and ultrasonic treatment at 100 W for 30 s. Under these conditions, egg white peptide liposomes with an encapsulation efficiency of (65.7 ± 3.6)% were obtained. Using 1% Tween-80 as a stabilizer, the liposomes had good storage stability for 30 days. In addition, the results of in vitro and in vivo release experiments demonstrated that the product had good slow-release properties, and the concentrations of six essential amino acids accumulated in the serum of mice gavaged with the liposomes to a maximum level significantly higher in that observed with egg white peptides. Particularly, tryptophan was released from the liposomes into the serum of mice 3.5 hours later and phenylalanine, valine and methionine were released 2 hours later than from egg white peptides. Among the six essential amino acids, the highest concentration of lysine increased the most (by 523.53%) in the serum of mice administered with the liposomes compared with mice given egg white peptides, while methionine concentration exhibited the least increase (by 109.31%). In this study, egg white peptide liposomes with stronger stability, higher entrapment rate and better sustained-release effect were obtained, which could potentially be a promising candidate for amino acid supplementation. The knowledge acquired in this study will provide potential technical support for the development of egg white peptide-based functional products.

Key words: high pressure homogenization; egg white peptide; liposomes; sustained-release