High efficiency desalination of wasted salted duck egg white and processing into food-grade pickering emulsion stabilizer

Abstract

Salted duck egg white (SDEW) is difficult to convert into high-value products for the high salt content and unpleasant odor, which leads to the loss of high-quality protein resources. In this work, for the first time, the freeze-thaw treatment was used for protein desalination to achieve complete desalination of SDEW. After SDEW prepared into hydrogel by microwave-assisted hydrothermal (125 °C, 500 W) in only 12 min, repeated freeze-thaw treatments made the hydrogel porous at the molecular level from the inside, which accelerated the outward migration of salt, thereby increasing the desalination efficiency. After ultrasonic dispersion, completely desalted SDEW, as a food-grade Pickering emulsion stabilizer, can stabilize Pickering emulsion at a particle concentration of 0.5–3.0%, oil phase fraction of 0.20–0.80 and pH value of 3.0–11.0 for at least 28 days. Overall, the findings provide a novel, simple and efficient method for SDEW desalination, and confirm that desalted SDEW is a low-cost but efficient food-grade Pickering emulsion stabilizer, which extend the potential commercial applications for SDEW in food industry.