According to nutrition experts, the nutritional value of preserved eggs is similar to that of duck eggs, and their taste is much better than that of duck eggs. However, it should be reminded that preserved eggs contain five times more sodium than duck eggs. Therefore, it is advisable for hypertensive patients to eat less.
Egg nutrition is similar to duck eggs
The production process of preserved eggs is more magical: a raw duck's egg is wrapped in straw for 30 to 40 days, and it turns into a dark green, transparent, preserved egg that can be eaten directly, and has a long aftertaste. After technical improvement, the preserved eggs are now basically mixed with white lime, tea, salt, noodles, ash, loess, rice husks, etc., and then the fresh crack-free duck eggs are packed one by one and sealed with plastic film. 30-40 days are preserved eggs.
In the preserved eggs, we often see the pattern of pine flowers appearing. This is actually caused by protein breakdown in preserved eggs and produced by alkaline substances. Similarly, the color of preserved eggs is due to protein in the strong alkali, the protein part will appear red brown or dark brown, egg yolks are dark green.
A hospital director of nutrition said that duck eggs from fresh to preserved eggs, the moisture content has decreased, protein, fat changes are not. However, the sodium content of preserved eggs is much higher than that of duck eggs. This is because during the production of preserved eggs, both salt and alkali added in the sludge contain sodium, which can penetrate into the preserved eggs through the tiny gaps in the shells. High sodium content is a risk factor for high blood pressure and should be eaten as appropriate.
More heavy metals, children eat less
For preserved eggs, the Chinese have never felt it disgusting, but it is the safety of consumers that they worry about. Yan Huawei said that lead oxide has been added to traditional formulas for processing preserved eggs in China because lead is a toxic heavy metal element, which seriously affects the nutritional value of preserved eggs and even relates to food safety issues. Therefore, after many studies, lead-free preserved eggs were produced. That is, a substitute material of lead oxide was found, among which EDTA and FWD have better use effects.
In addition, preserved eggs in addition to lead, often also contain heavy metals such as zinc and mercury, children's absorption of heavy metals is relatively strong, so to remind parents to pay attention, or less to children eat preserved eggs. To eat preserved eggs, we must also buy preserved eggs produced by regular manufacturers.
Preserved eggs, duck nutrition PK
(Unit: protein, fat, g / 100 g, calcium, potassium, sodium, iron, mg / 100 g)
Name Moisture Protein Fat Cholesterol Calcium potassium sodium Iron
Duck Egg 70.3 12.6 13.0 565 2.09
Preserved egg 68.4 14.2 10.7 608 3.3
Tips:
How to buy a preserved egg?
After laying eggs, the eggshell is better than blue. Yan Huawei said, the following two methods can test out a good preserved egg ---
(1) Put the egg in your hand and throw it up slightly. Even throw it a few times. If you feel a sense of elastic tremor, and the heavier one is a good egg, on the other hand, it is a poor quality egg;
(2) Hold the two ends of the egg and shake it up and down in the ear to hear the sound of water or percussion. If you can't hear the sound, then it is a good egg.