Reinforced pickering emulsions stabilized by desalted duck egg white nanogels with Ca2+ as binding agents

Abstract

The inadequate utilization of salted duck egg white has become a serious problem for the food manufacturing in the past few years. Hence, in this study, we attempted to fabricate a kind of Pickering emulsion system based on the duck egg white nanogels (DEWN), with Ca2+ as the potential stabilizer, aiming to find out a more effective way to reuse these salted duck egg white products. As demonstrated, when cross-linked by Ca2+, the fabricated DEWN and Ca2+ combined particles (abbreviated as DEWN-Ca) showed a downtrend in surface wettability with increase in Ca2+ concentrations. Subsequently, the corresponding emulsion formulations with distinct Ca2+ concentrations or oil phase contents were further investigated and the results showed a decrement in the droplet sizes by adding Ca2+ firstly (Ca1), while the increment was exhibited with continuously added Ca2+ (from Ca2 to Ca5). The interfacial and rheological properties were further explored as well. Briefly, in comparison of DEWN-based system, the addition of Ca2+ did reduce both the interfacial tension and the values of G’ and G”. Moreover, it is noteworthy that the addition of Ca2+ could also increase the freeze-thaw and heat stability of the obtained emulsion systems. Collectively, our findings not only unlocked an effective method to achieve the re-utilization and expand the application of salted duck egg white, but also highlighted a universal way in exploiting and applying the Pickering emulsion systems.