Emulsifying properties of glycation or glycation-heat modified egg white protein

Abstract To investigate the potential of glycation and/or heat modified egg white protein (EWP) as stabilizer for oil-in-water emulsions, glycated EWP (GEWP) was prepared by a dry-heated Maillard reaction using EWP and isomalto-oligosaccharide. Heat-induced GEWP nanoparticles (HGN) were then fabricated by heating GEWP at 90 °C for 30 min at pH 6.0–9.0. The physicochemical characteristics (particle diameter, ζ-potential and surface hydrophobicity) and emulsifying capacity of GEWP and HGN were investigated. In addition, the storage, oxidation, thermal treatment and salt stabilities of emulsions prepared with GEWP and HGN were evaluated. The results indicated that the emulsions prepared with modified EWPs exhibited higher protein adsorption on the oil-water interface and smaller particle size. The GEWP- and HGN-stabilized emulsions were stable against droplet aggregation during storage and exhibited better oxidation stability, which may be related to the enhanced antioxidant activity and absorption ability of the modified EWPs. Additionally, the emulsions prepared with GEWP and HGN exhibited higher heat and salt stabilities due to the increase in surface hydrophobicity and net charge. The thermostable structure of the proteins induced by glycation and heat treatment also contributed to the improvement in heat stability. Overall, the HGN-stabilized emulsions exhibited the best physicochemical stability among the modified EWPs.