Salted duck eggs have bluish-green shells, a round and smooth appearance, and are also known as "green fruit." Salted duck eggs have a long history in China and are deeply loved by the common people, making them a favorite in the market. The product is characterized by its red yolk and rich nutritional value. It is rich in fat, protein, and various amino acids required by the human body, as well as various minerals such as calcium, phosphorus, and iron, 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 flavor, suitable for all ages.
Compared to regular duck eggs, some proteins in salted duck eggs are broken down into amino acids. Due to the brining process, the salt content inside the egg increases, and the inorganic salts also slightly increase. The fat in the raw egg yolk is combined with protein, so it is not visible as oil. After a long curing time, the protein denatures and separates from the fat. The fat then gathers together to form egg yolk oil. The yolk contains red-yellow yolk pigment and carotene, which dissolve in the egg yolk oil to present a red-yellow color, enhancing the sensory qualities of the salted egg. The oozing of oil from a salted duck egg is a sign that it is well-cured. In addition, salted duck eggs are rich in inorganic salts such as calcium and iron. The calcium and iron content is higher than that in 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 quality salted duck egg is: high-quality cured eggs have clean shells, and when shaken, they have a slight trembling sensation. After peeling, the saltiness is moderate, and it is rich in oil with a great taste. When poked with a chopstick, yellow butter will emerge. The yolk is layered, with each layer getting progressively darker and redder towards the center. In contrast, poorer-quality eggs have dull shells with white or black spots, are easily broken, and have a shorter shelf life. After peeling, the white is soft, mushy, and overly salty.