Eggs mainly refer to poultry eggs, including chicken, duck, goose eggs, and some other poultry eggs, such as quail eggs, pigeon eggs, etc. are also edible. The bulk consumption and consumption of daily residents is mainly eggs. Eggs are mainly composed of three parts: eggshell, egg white, and egg yolk. Taking regularly consumed eggs as an example, each egg weighs about 50g, and the weight of the eggshell accounts for about 11% of the weight of the whole egg.
The nutritional content of eggs is about the same. Eggs are a source of high-quality protein, with a protein content of around 13%; Fat content about 10%-15%; The carbohydrate content is low, about 1.5%; Rich in vitamins, more complete, including all B vitamins, vitamin A, vitamin D, vitamin E, vitamin K, trace amounts of vitamin C; The mineral content is 1.0%-1.5%, of which phosphorus, calcium, iron, zinc and selenium are higher. The fats, vitamins, and minerals contained in eggs are mainly concentrated in the yolks.
Today, let's talk about the precautions for egg consumption and common egg products.
Precautions for egg consumption
1. Discarding egg yolks is not advisable
Lipids are a general term for lipids contained in blood, including cholesterol. Existing research results confirm that the main harm of hypercholesterolemia is easy to cause coronary heart disease, stroke and other atherosclerotic diseases. Cholesterol is mainly concentrated in egg yolk, and the cholesterol content per 100g of egg yolk ≥ 1500mg, based on this, some people with dyslipidemia often "stay away" from egg yolk. This is not the case, the daily synthesis of cholesterol in the human body is about 1-1.2g, and the cholesterol derived from the diet accounts for 1/7-1/3 of the cholesterol synthesized in the body. Therefore, the "Dietary Nutrient Reference Intake for Chinese Residents (2013 Edition)" deletes the upper limit of dietary cholesterol (the upper limit of cholesterol in the 2000 version is 300mg/d) (Note: mg/d: mg/day).
2. Do not eat raw eggs, do not drink raw egg whites, and beware of salmonella infection
The protein of raw eggs is gelatinous, which is not easy for the human body to digest and absorb; Raw egg whites contain anti-avidin, which affects the absorption of biotin, and antitrypsin substances, which inhibits trypsin activity and hinders protein digestion. Birds can transmit Salmonella directly to shelled eggs via the ovaries. When boiling eggs, at least the internal temperature > 75 ° C, the eggs should be boiled until the yolk becomes solid, do not eat all kinds of half-cooked eggs.
The advantages and disadvantages of these three common egg products
How much do you know?
1. Pine eggs: B vitamins are almost completely destroyed, and there is a problem of lead contamination
Pine eggs, also known as preserved eggs, changed eggs, colored eggs, etc. Pine flower eggs are a famous product in China, and their production is invented and created by China's working people in long-term life practice. Pine eggs are generally made from fresh duck eggs through special processing methods. The processed finished product has a certain difference from fresh eggs in the composition and content of nutrients.
The water content of pine eggs is less, so the protein content is slightly increased, especially due to the action of alkali and salt added during processing, the content of minerals in pine eggs increases significantly. After fresh duck eggs become pine eggs, the composition of nutrients changes, and the nutritional value also changes to a certain extent, especially in B vitamins, which are almost completely destroyed due to the action of alkali, reducing the nutritional value of egg vitamins.
In addition, in the process of making pine flower eggs, sometimes a certain amount of lead is added to improve its appearance product quality, but lead is a harmful element for the human body, therefore, there are some new processing methods, so that pine eggs become lead-free or low-lead eggs, more in line with human health.
2. Salted eggs: should not eat more, be vigilant of excessive daily salt intake
Salted eggs, also known as pickled eggs, salted eggs. China's production of salted eggs has a long history, a long time ago, our working people put fresh poultry eggs in brine storage, and later found that the eggs stored in brine not only do not deteriorate for a long time, but also have a special flavor. Therefore, this method of storing eggs in brine gradually evolved into a method of processing salted eggs. The processing method of salted egg is simple and easy, the processing cost is low, the processing technology is easy to master, the product flavor is special, and it is convenient to eat, which is deeply loved by consumers. After fresh eggs are pickled into salted eggs, due to the role of salt, the proportion of nutrients in the eggs has changed, due to the osmosis of salt, the water content of salted eggs is reduced than that of fresh eggs, while the content of fat, carbohydrates and other content has increased, protein may be partially exuded, the content decreases, and the content of inorganic salts such as calcium rises significantly.
On the whole, the nutritional value of fresh eggs and salted eggs does not change greatly, but it should be noted that because salted eggs use salt during the pickling process, in the case of a relatively long marinating time, more sodium in the salt enters the egg. The "Dietary Guidelines for Chinese Residents (2022)" recommends that adults consume no more than 5g of salt per day. Therefore, it is not advisable to eat more, especially in patients with high blood pressure and kidney disease.
3. Bad eggs: unique flavor, high calcium content, is a good cold food
Rotten eggs are made from high-quality fresh duck eggs made with glutinous rice sake lees. The shell of the finished egg is completely or partially shed, and only the membrane under the shell wraps the contents of the egg, which is an egg product like a soft shell, so people are also called soft shell bad eggs. Its egg quality is delicate and tender, the yolk is orange-red semi-solidified, the smell is fragrant, and the taste is evocative after eating, which is a unique cold food in China.
In the process of spoiling eggs, the alcohol generated can solidify and denature the egg white and egg yolk, and make the egg have a slight sweetness, while producing alcohol, it can also produce acetic acid, so that the eggshell is softened, and the calcium salt in the eggshell penetrates into the film on the surface of the egg by osmosis, so the calcium content of the bad egg is particularly high, about 40 times higher than that of ordinary fresh eggs. Therefore, it is an egg product with high nutritional value. Text/Gao Chunhai (Physician and registered dietitian, Tianjin Center for Disease Control and Prevention)