The effect on quality of pickled salted duck eggs using the novel method of pulsed pressure osmotic dehydration

Abstract

Salted eggs are a popular food or jardinière. In addition, this is the most traditional method to preserve eggs. A conventional method for pickling salted eggs is time-consuming, strenuous, and difficult to control. The pulsed pressure osmotic dehydration (PPOD) technology uses pulsed pressure of osmotic solution to increase the pickling efficiency greatly. Previous reports have successfully applied PPOD for preparing salted hen eggs. However, there are no reports about the application of PPOD for pickling duck eggs due to thicker shell and low consistency. In this article, the time of 180 kPa pressurization was optimized for the pickling process by assessing the salt content, weight gain, yolk index, and sensory evaluation. The pressurization time of 7.5 min resulted in superior salinity, grittiness, and taste properties of cooked salted eggs. Additionally, oil exudation, texture change, moisture content and distribution, shell, and shell membrane microstructure were studied during pickling using the optimized process. It was determined that pulsed pressure favored higher oil exudation by increasing the hardness and viscosity of solidifying and exudating the egg yolk (EY) oil. Meanwhile, pulsed pressure can change the shell and shell membrane microstructure as well as water distribution to facilitate gas and salt penetration. In conclusion, appropriate PPOD processing conditions (i.e., 180 kPa pressure, 7.5 min pressurization time followed by 40 s pressure-releasing time) have been recommended for pickling duck egg. These parameters result in high processing efficiency and high product quality. Practical applications The pulsed pressure osmotic dehydration (PPOD) technology uses pulsed pressure of osmotic solution to increase the pickling efficiency greatly. Our research can provide guidance for the further application of PPOD. And PPOD can also provide an effective way to replace the traditional pickling method.