Abstract:The traditional mud-packing method for preparing salted sea duck eggs has drawbacks of long pickling time, high salt content, and inconsistent quality. This study improved the traditional mud-packing method and clarified the change patterns of the physicochemical properties and quality of sea duck eggs during pickling. The results showed that mature salted sea duck eggs prepared using the improved mud-packing method exhibited a mass change rate of 1%~3% and salt content of 3.0%~3.4% in egg white, which were much lower than those (2%~-6% and 4.4%) of mature salted sea duck eggs prepared using the traditional mud-packing method. Additionally, the mass change rate of duck eggs significantly increased when using a pickling solution with a salt mass fraction below 20% (P<0.05). The two methods did not differ much in the decreasing trend of water content in egg white during pickling, whereas the traditional and improved methods decreased the water content of egg yolk from 45% to 22% and 17%, respectively. The salt contents of egg white and yolk increased from 0.2% to 3%~4% and 0.9%~1.2%, respectively, indicating that the salt content increased more significantly for egg white. Furthermore, the salt mass fraction significantly impacted water removal and salt infiltration (P<0.05). On day 25 of pickling, the improved method resulted in an oil yield and sandiness exceeding 65% and 90%, respectively, and the yolk texture properties reached the level of those on day 40 when using the traditional method. Moreover, the yolk particle structure became loose, and the formation rate of the hard inner core in yolks was obviously reduced. On day 40 of pickling, the improved method resulted in a salt content in egg white below 4% and a salt content in egg yolk over 0.9%. Therefore, compared with the traditional method, the improved mud-packing method reduced the saltiness of mature salted duck eggs without lowering their oily, loose, and sandy quality. This study can provide a theoretical basis for improving the traditional mud-packing method and optimizing the quality of salted duck eggs.
