Concentration effect of epigallocatechin-3-gallate-bovine bone protein conjugates on emulsion stability.

To improve the application of bovine bone protein (BBP) in the food industry, epigallocatechin-3-gallate (EGCG) was modified to EGCG-BBP conjugate. The effect of EGCG-BBP concentration on the emulsifying and oxidative stability of emulsion during the storage period was studied. After covalent modification, the molecular weight of EGCG-BBP increased, while lower maximum fluorescence intensity and the content of α-helix and β-sheet were decreased. The droplet particle size and ζ-potential of emulsion significantly decreased with increasing concentration of EGCG-BBP. Overall, the emulsion prepared by 0.6 % EGCG-BBP was the best, which had the lowest size (723.5 nm) and highest negative charge (−34.18 mV), and smallest droplets, indicating the improved physical stability of the emulsion. Additionally, the peroxide value and thiobarbituric acid reactive substances value of the EGGCG-BBP emulsion significantly decreased to after 20 d of storage. Moreover, the EGCG-BBP stabilized emulsions exhibited strong antioxidant capacity in vitro in an EGCG-BBP concentration-dependent manner. Mechanistically, EGCG-BBP improved the physical and oxidant stability of the emulsion by forming a thicker surface film and increasing the surface charge of droplets. This study demonstrated that EGCG-BBP conjugate can improve the emulsion stability, suggesting that BBP can be used in emulsified food. [Display omitted] • BBP-EGCG conjugate prepared via alkali induction method was as antioxidant emulsifier. • Physical stability of emulsion prepared by EGCG-BBP was significantly improved with the increase of EGCG-BBP concentration. • The addition of EGCG-BBP also significantly improved the chemical stability of the prepared emulsion. • Emulsion prepared by 0.6 % EGCG-BBP had the best stability. [ABSTRACT FROM AUTHOR]