Physical and oxidative stability of oil-in-water (O/W) emulsions in the presence of protein (peptide): Characteristics analysis and bioinformatics prediction

The physical and oxidative stability of soybean protein hydrolysate-stabilized oil-in-water (O/W) emulsions created via limited hydrolysis using Alcalase (15, 30, 45, 60, 90, 120, and 180 min) was investigated. The extracted emulsion protein exhibited significantly lower surface hydrophobicity, higher antioxidant properties, and a greater proportion of beta-sheet and alpha-helix structures than soybean protein isolate. The physical stability of the emulsions was characterized by particle size, zeta-potential, rheological property, and multiple light scattering. The emulsion obtained by enzymatic hydrolysis for 90 min (90 min-E) had the highest physical stability, showing the smallest droplet size, uniform droplet distribution, lowest zeta-potential, lowest Turbiscan stability index, and larger G ' and G ' values. It also exhibited the highest oxidative stability, as evidenced by the thiobarbituric acid-reactive substances test. Due to the good physical and oxidative stability of 90 min-E, LC-MS/MS analysis and bioinformatic tools (Chou-Fasman secondary structure prediction and the BIOPEP database) were conducted on the protein extracted from 90 min-E. These data provided insight into the mechanism of emulsionstabilizing action by the emulsion protein (peptide) and identified potential bioactive peptides. This new strategy of producing stable O/W emulsions will likely expand its application to nutrient components or effective wall materials.

Automated summary

Soybean protein hydrolysate-stabilized oil-in-water emulsions created via limited hydrolysis with Alcalase exhibited superior physical and oxidative stability, with the emulsion produced by enzymatic hydrolysis for 90 minutes showing the best stability. LC-MS/MS analysis and bioinformatic tools were used to study the mechanism behind the emulsion-stabilizing action and identify potential bioactive peptides in the extracted protein from the 90-minute emulsion.