Because chickens eat a lot of food rich in carotene, such as vegetables and insects, these food pigments enter the yolk, which has a certain impact on the color of the yolk. Therefore, under normal circumstances, the yolk of the soil egg is dark yellow, much like the color of sunset red, which is darker than the yolk of ordinary eggs.
2 Is it authentic that the egg yolk is not yellow? The method of judging the egg yolk color is not suitable, and it is impossible to determine whether it is authentic or not.
Many people often judge whether it is a native egg from the color of the yolk. They think that yellow is a native egg and light is not a native egg, but in fact, there are two main factors that determine the color of the yolk:
One is the time when the yolk is produced. At the peak, an egg is laid every 24 hours on average. The pigment deposition time in the feed is short, the amount of deposition is small, and the color is naturally light.
The second factor is the pigment content in the feed, which mainly refers to lutein, lycopene, leaf green, zeaxanthin, etc. The higher the pigment content, the more pigments are deposited per unit time, and the darker the color.
When eggs are formed in hens, fat-soluble pigments are deposited around the oocyte with fat and other substances to provide the color of yolk. Lutein is one of the representatives, and it is a carotenoid. Animals can't produce carotenoids themselves, but they can only get them through the food chain.
For purely stocked chickens, how much lutein it can ingest depends entirely on the stocking environment. For example, if you can eat grass, insects and other egg yolks in summer, the color of the egg yolks will be darker. If the chickens eat less lutein in winter, the color of the egg yolks will be lighter. The lutein ingested by caged and large-scale commercial laying hens depends on the feed.
Because eggs with darker yellow are more in line with people's needs, breeders usually add lutein to the feed or use a feed additive called Mylabris yellow. In the Catalogue of Feed Additives (20 13) No.2045 issued by the former Ministry of Agriculture, Mylabris yellow can be used as a colorant in poultry feed, and there is no specific limit on the amount of this additive. It will not affect human health, but it can make the egg yolk look better, so it is impossible to tell whether it is a native egg simply from the color of the egg yolk. After all, the color of the egg yolk can be manipulated artificially.
The best way to identify native eggs is that there is no difference between native eggs and ordinary eggs in terms of nutritional composition and edible value, and it is not important to identify them from the point of view of eating. Moreover, in order to satisfy everyone's pursuit of native eggs, cage eggs are almost the same as native eggs in appearance and other aspects, and there is no difference at all. It is suggested that whether you buy "cage eggs" or "native eggs", the most important thing is that the products should be safe and healthy, standardized production, and try to choose eggs produced by well-known brands.
4 How many children and old people can eat eggs a day at most 1 egg a day, and it is more appropriate for teenagers and adults to eat 2 eggs a day.
Eggs are rich in nutrients, including protein, lecithin, cholesterol, minerals, vitamins, etc. Eating too many eggs will lead to overnutrition, which will lead to the accumulation of nutrients into fat in the body and cause obesity; Moreover, egg yolk is rich in cholesterol. If you eat too much, you will consume too much cholesterol, which will affect the health of blood vessels and lead to cardiovascular and cerebrovascular diseases.
At the same time, excessive intake of protein will not only be absorbed by the body, but also cause waste of protein, and will also cause waste and waste gas in the intestines, which will increase the digestive burden of the stomach and affect the health of the digestive system.