1. Pickled salted duck eggs are mainly pickled with salt. When fresh eggs are pickled, the salt in the salt mud or salt solution outside the eggs seeps into the eggs through the eggshell, shell membrane, and yolk membrane, and the water in the eggs also continuously seeps out. When the eggs are pickled and mature, the salt concentration contained in the egg liquid is basically similar to the salt concentration in the puree or salt water solution. Hypertonic salt causes water to escape from the cell body, thus inhibiting bacterial life activities. At the same time, salt can reduce the activity of proteases in eggs and the ability of bacteria to produce proteases, thereby slowing down the rate of egg spoilage. The penetration of salt and the leakage of water change the original properties and flavor of the eggs.
The amount of salt used in pickling salted duck eggs varies with regions and habits. When using a high-concentration salt solution, the osmotic pressure is high, the water is lost quickly, the taste is too salty and the taste is not fresh; if the salt amount is less than 7, the preservative ability is poor. At the same time, the soaking time is extended, the maturity period is delayed, and the nutritional value is reduced. In short, using too much salt will hinder the flavor of the finished product, while using too little salt will fail to achieve the purpose of preservation. Based on the weight of eggs, the amount of salt used is generally about 10, which can be adjusted appropriately according to local habits.
2. Changes in the pickling process As the pickling time increases, the salt content in the egg whites increases significantly, while the salt content in the yolks does not increase much; the water content of the egg yolks decreases significantly, while the salt content in the egg whites decreases significantly. The amount of water does not decrease significantly; the viscosity of the egg white gradually becomes thinner and becomes a water-like substance, while the concentration of the egg yolk increases, becomes thicker and appears in a solidified state; the pH value of the egg white does not change significantly; the oil content in the egg yolk rises rapidly, which is more obvious after 10 days of pickling. , then rises slowly; the oil content of the egg yolk is of great significance to the flavor formation of pickled salted duck eggs. Due to the loss of moisture, pickled salted duck eggs lose slightly in weight during the pickling process.
The purity of the salt used in pickling affects the flavor of the eggs. For example, when the calcium and magnesium ion content in the salt reaches 0.6, it will taste bitter. Therefore, pure salted duck eggs generally need to be used for pickling. Reprocessed salt or sea salt.
The higher the concentration of salt, the faster the salt will penetrate into the eggs, resulting in faster maturation and shorter pickling time; the higher the pickling temperature, the faster the salt will penetrate into the eggs, resulting in faster maturation and shorter pickling time. Therefore, the amount of salt used during pickling should be determined according to the temperature during pickling and consumer preferences. It is necessary to prevent the eggs from spoiling and prevent consumers from feeling too salty.
When mixed with salt mud or ash for pickling, the salt penetrates into the eggs slowly and takes a long time; when soaked in salt water, the salt penetrates into the eggs faster and the pickling time can be shortened.
The protein of fresh eggs is thick, the penetration and diffusion of salt are slow, and the ripening of pickled salted duck eggs is also slow; conversely, the ripening of pickled salted duck eggs will be faster.
To obtain high-quality pickled salted duck eggs, you must use fresh eggs and flexibly control the amount and concentration of salt, ambient temperature and pickling time according to different pickling methods.