1, look at the appearance

The color of the deteriorated preserved eggs is poor and the protein does not change color; The air chamber is large and there are many dewdrop bubbles. Observe whether its appearance is complete, whether there is damage, mildew and so on. Poor preserved egg packaging materials are damaged or moldy; After peeling off the wrapping material, the eggshell has spots, breakage and leakage, and some contents have been polluted; After shaking, there is a sound of water swinging or a feeling of light floating.

2. Touch check

Peel off the preserved egg, and the deteriorated preserved egg has poor elasticity and weak egg body. When touching, the yolk is soft and big, and the protein is sticky and slippery.

3. Smell the smell

Preserved eggs that go bad when they are cut, the yolk has black liquid flowing out and has a light or heavy odor. The whole preserved egg is solidified, non-sticky, clean and elastic, translucent brown, with loose pattern texture; When the egg is cut vertically, it can be seen that the yolk is light brown or light yellow with a thin center. Deteriorated preserved eggs have a pungent odor or a musty smell.

4. Light transmission method

The preserved eggs were identified according to the light transmission method of fresh eggs after the wrapping was removed, and the color, solidification state and air chamber size of the eggs were observed. The contents of deteriorated skin and balls are not solidified, but are water-like and have large air chambers.

Extended data

Matters needing attention in selecting preserved eggs:

1, there are black spots on the surface of eggshell, which indicates that the preserved egg contains a high content of lead and copper. After the eggshell is peeled, some proteins may be dark green or have black spots, which is the result of the reaction between sulfur produced by protein decomposition and metal ions (such as copper ions).

2. The traditional preserved eggs are pickled with fresh duck eggs, edible alkali, edible salt, quicklime and other raw materials, and the pickling time is more than 2 months. However, in order to shorten the production cycle and reduce the cost, some unscrupulous manufacturers use industrial copper sulfate for pickling.

3, such preserved eggs will increase the burden of liver and kidney, and long-term consumption in large quantities will easily cause heavy metal poisoning. Therefore, we should try to choose preserved eggs with gray skin, no black spots, no cracks and complete eggshells.

reference data

People's Network-It's safest to buy preserved eggs with fewer spots.