Salted duck eggs have a greenish shell, a round and smooth appearance, and are also known as "green fruit." With a long history in China, salted duck eggs are deeply loved by the common people and are highly favored in the market. The product's characteristics are a red yolk and rich nutritional value. It is rich in fat, protein, and various amino acids required by the human body, as well as multiple minerals and various trace elements and vitamins essential for the human body. Moreover, it is easily absorbed by the body. High-quality salted duck eggs have a moderate saltiness and a delicious taste, suitable for all ages.
Compared to regular duck eggs, some of the protein in salted duck eggs is broken down into amino acids. Due to the brining, the salt content inside the egg increases, and the inorganic salts also slightly increase. The fat in the raw egg yolk is bound to the protein, so it does not appear to contain oil. After a long curing time, the protein denatures and separates from the fat. The fat then gathers to form egg yolk oil. The yolk contains red-yellow lecithin and carotene, which dissolve in the egg yolk oil to appear red-yellow, enhancing the sensory qualities of the salted egg. The presence of oil from the yolk is a sign that the egg is well-cured. Additionally, salted duck eggs are rich in inorganic salts such as calcium and iron, with higher calcium and iron content than chicken eggs and fresh duck eggs, making them a good food for supplementing calcium and iron in the summer.
However, no matter how good a food is, it should not be eaten without restraint. The salt content in salted eggs is generally around 10%, and eating too much can easily lead to high blood pressure.
A simple method to identify a good salted duck egg is as follows: high-quality cured eggs have a clean shell and a slight tremor when shaken. After peeling, the saltiness is moderate, it is oily and delicious, and when poked with a chopstick, buttery oil emerges. The yolk is layered, with each layer being darker than the last, and the deeper you go, the redder it becomes. In contrast, inferior eggs have a dull shell with white or black spots, are easily broken, and have a shorter shelf life. After peeling, the white is soft, mushy, greasy, and overly salty.