Why can salted duck eggs still flow out of oil if they are not salty

hello! The oily salted duck eggs are processed, not processed by chemicals. I will talk about it in detail below: 1. Why can salted duck eggs produce oil? As we all know, duck eggs contain 14 to 16% fat, most of which is in the yolk. If the egg white is removed, the fat in the egg yolk accounts for about 36%. There is much water in the egg (about 71%), and the fat is mixed with protein, inorganic salts and other substances. Therefore, no matter raw or cooked duck eggs, there is no oil in the yolk. If the salt penetrates into the egg after salting, part of the water in the egg yolk is forced to penetrate outward, so the fat is concentrated and accumulated. After the salted duck eggs are cooked, the protein in the yolk solidifies, so we can see that there is a lot of oil in the salted duck eggs. Second, the principle of salted duck eggs producing oil: part of protein in salted duck eggs is decomposed into amino acids. Due to salting, the salt in eggs increases, and the inorganic salts in eggs also increase slightly. Because the fat in raw egg yolk is combined with protein, it can't be seen that it contains fat. After a long curing time, protein will denature and separate from the fat. When the fat is gathered together, it becomes egg butter, which contains red and yellow vitellin and carotene. When dissolved in egg butter, it is red and yellow, which increases the sensory properties of salted eggs. The oily salted duck eggs are a sign of good curing. thank you