Enzymatic catalyzed corn fiber gum-bovine serum albumin conjugates: Their interfacial adsorption behaviors in oil-in-water emulsions

Abstract

The purpose of present study was to investigate the interfacial behaviors of the peroxidase-catalyzed intermolecular conjugates of corn fiber gum (CFG) and bovine serum albumin (BSA) (gum and protein weight ratio of 4:1). CFG-BSA conjugate stabilized emulsion remained stable with low flocculation and coalescence degree during storage in comparison to single BSA or CFG emulsion, attributing to its higher amount of adsorbed protein and polysaccharide. As shown by SDS-sulfate polyacrylamide gel electrophoresis, the adsorbed protein at the surface of oil droplets stabilized by CFG-BSA conjugate was partly crosslinked with CFG, forming an entangled emulsion network with increased apparent viscosity. Adsorbed CFG-BSA conjugates distributed loosely around the droplet interfaces as revealed by images of confocal laser scanning microscopy. Their interfacial layer thickness was estimated to be 85.1 nm using a monodisperse polystyrene latex particle model, which was not only larger than the adsorbed layer thickness of single CFG (71 nm) or BSA (6.9 nm) but also their combined layer thickness. To our knowledge, it is the first time that the interfacial properties of enzymatically-crosslinked polysaccharide and protein have been studied.