What to look for when buying chicken eggs? What is the difference between dietary and canteen? How long can eggs be stored and how to avoid salmonellosis? 9 answers to the most popular questions about this product.
1. How to read the stamp on an egg?
The letter “d” or “c” means, respectively, a dietary or table egg. The first sign on the stamp indicates the date - the day and month of the “birth” of the egg, the second - the category (and therefore its size).
2. What is the difference between a dietary egg and a table egg?
A diet egg (with a red stamp) differs from a table egg in its freshness. It must be implemented within 7 days from the moment of birth. Then, after a week, the egg goes into the table category. If the egg is initially doomed to a long life, long-term sales and, possibly, storage at sub-zero temperatures, a stamp is applied to it with blue ink.
3. How long can an egg be stored?
A table egg can be stored at room temperature for up to 25 days from the moment of “birth” and up to 90 days in the refrigerator
4. Which category of eggs is better?
- The third category is the smallest eggs (35-44.9 g).
- The second category is medium (45-54.9 g).
- The first category is large (55-64.9 g).
- Selected ones (indicated by the letter “o”) are the largest (65-74.9 g).
By the way, in culinary recipes an egg weighing 40 g is taken as one egg, that is, an egg of the third category.
5. White or dark?
Experts have no disagreement on this matter: the color of the eggs is just a tribute to the breed of the chicken. This is a purely aesthetic point that does not in any way affect the quality of the product.
6. What are “enriched eggs”?
“Smart” eggs with iodine, “fitness” eggs with selenium, and “vitamin” eggs are increasingly appearing in stores. Enrichment of eggs with various microelements occurs through the addition of appropriate preparations to the feed of laying hens. Whether such a product is useful for you or not is an individual question - if you do not know the level of iodine in your body, it is better not to experiment with eggs enriched with this element.
7. What does “organic” mean on egg packaging?
Abroad, the appearance of this word on product packaging is strictly regulated. It means that these are eggs from chickens that have the opportunity to freely range in natural fields under the sun, which are fed exclusively with natural feed, rich in chlorophyll, and in winter - seaweed. In our country, although a resolution on sanitary and hygienic requirements for organic products was adopted (in the summer of 2008), testing for compliance with the declared standards has not yet been carried out.
All that remains is to express gratitude to those manufacturers who themselves send their products for voluntary laboratory research, for example, to the Institute of Nutrition of the Russian Academy of Medical Sciences. In general, read the labels on the packaging more carefully.
8. How to protect yourself from salmonellosis?
- Cracked eggs should not be eaten.
- Before use, the egg should be washed with soap or soda (dried droppings are not at all a sign of an “organic” egg, but rather a consequence of poor hygiene at the poultry farm).
- Always wash your hands with soap if you handle eggs.
- Do not eat raw eggs or add them to dishes.
- It is recommended to boil eggs for at least 10 minutes.
9. What are the storage conditions for eggs?
Eggs are stored in a cool place away from strong-smelling foods and away from raw meat. The optimal temperature is 0-5°C. To protect them from foreign odors, use an airtight tray. Experts advise storing eggs with the pointy end down - otherwise the yolk, located on the air chamber of the egg, will begin to dry out faster.
It is one of the staple foods of the population of many countries. But despite the popularity of this product, people quite often face the problem of choosing them. It turns out that chicken eggs come in several categories, each of which has its own shelf life and a lot of other information that is incomprehensible to most. Let's look at what types of eggs there are and how to choose them.
Acceptable storage period
The shelf life of a product is the first thing we usually focus on when purchasing. Chicken eggs are no exception. Depending on the time that has passed since the hen laid eggs, they are usually divided into two types: dietary and table.
Dietary "D"
Dietary specimens include: the shelf life of which does not exceed 7 days, not counting the day the hen laid eggs. However, they should not be at sub-zero temperatures. Moreover, this species must have a compacted white, an equally colored yolk, and a height of the space occupied by air of no more than 4 mm. The shell of such eggs must be clean; a small presence of dots or stripes on it is allowed. 
You can recognize this product on the counter by a red stamp on the shell with the letter “D” on it. Thus, this species is not a specific variety or species - it is simply the freshest eggs.
Did you know?A laying hen produces on average 250-300 eggs in 12 months. It takes her a little more than a day to lay one egg.
Dining rooms "C"
It is customary to include specimens that are stored at living room temperature as canteens. no more than 25 days from the date of their sorting, not counting the day of their demolition, or stored in refrigerated chambers for no longer than 90 days. Such a product has a mobile yolk, low protein density and a height of space occupied by air of more than 4 mm, which, as a rule, ranges from 5 to 7 mm. 
If dots and stripes are present on the shell, their total number should not occupy more than 12.5% of the total surface. A blue stamp is placed on the shell of each table egg indicating the capital letter “C” and its category.
Categories of chicken eggs and their weight
So, you and I know what types of chicken eggs there are and what is their difference. Now let's try to understand their categories. The key criterion by which eggs are classified into one category or another is their eggs, therefore, according to modern GOSTs, there are 5 main categories. 
Highest category (B)
Choice Egg (O)
Products in this category are slightly smaller in size and weight - from 65 to 74.9 g. Indicated on the shell or packaging with a large letter “O”. 
First category (C1)
Second category (C2)
Category 2 includes those eggs that have weight from 45 to 54.9 g. Such products are usually designated by the number “2”. 
Third category (C3)
Did you know?Every year, about 570 billion chicken eggs are consumed worldwide.
Thus, if you see a chicken egg on the counter with a mark on the shell “C2”, this means that it is a table egg of the second category, and the abbreviation “D1” classifies the product as a dietary product of the first category.
In addition, on store shelves you can often find products labeled "premium", "bio" and "organic control". However, we advise you not to fall for this trick of manufacturers and not to overpay extra money. 
The thing is that abroad this designation implies that those who demolished them the chickens are free-range and fed exclusively with natural food. However, our GOSTs do not provide any requirements for these inscriptions, so the above text does not guarantee you anything.
It is worth noting that the manufacturer may not label any of the above types and categories at all, if at the same time he packs the products in containers with a label that shows all the information necessary for the buyer. 
But the main condition is that the manufacturer must place the testicles in such packages that cannot be opened without leaving visible damage. This condition guarantees the buyer in the future that the contents of the container cannot be re-sorted or replaced.
Choosing an egg: how to protect yourself from infections
After receiving the above information, choosing eggs of the desired type and category will not be difficult. 
However, when purchasing, we still advise you to pay attention to the following:
- First of all, check the production date, which must be present on each copy or packaging.
- Pay attention to the manufacturer, which is recommended to be chosen based on the distance from the factory to the counter: the shorter the product was in transit, the better.
- The next step is to check whether the egg is rotten. To do this, simply bring it to your ear and shake it a little. If at the same time the yolk knocks against the wall of the shell, it is better to put it aside.
- The storage location of the goods in the store is also important, since the products in question are susceptible to strong absorption of unpleasant odors. It is also worth paying attention to this when purchasing goods in packaging: carefully check that there are no stains or mold on it.
- Well, the last important argument when choosing is appearance. Make sure that there are no cracks or chips in the shell, as bacteria can penetrate through them.
I would also like to note the false opinion that has developed among people that the larger the egg, the more useful substances it contains. In fact, large specimens are laid by older hens, so they contain much less nutrients than those laid by a young hen. Scientists call eggs of the first category the most optimal option for the human body. 
However, even with such careful selection, it is not always possible to avoid infection.
I think everyone has wondered what the markings on eggs mean.
According to current Russian standards, every egg produced at a poultry farm must be marked. The first character in the labeling indicates the permissible shelf life:
The letter “D” stands for dietary egg; such eggs are sold within 7 days.
The letter “C” stands for a table egg, which is sold within 25 days.
The second sign in the marking indicates the category of the egg depending on its mass:
Third category (3) - from 35 to 44.9 g.
Second category (2) - from 45 to 54.9 g.
First category (1) - from 55 to 64.9 g.
Selected egg (O) - from 65 to 74.9 g.
Highest category (B) - 75 g or more.
Thus, the marking “SV” is indicated on table eggs of the highest category, and “D1” is indicated on dietary eggs of the first category.
Regardless of the category of chicken egg, manufacturers can give it a number of interesting properties. For example, there are eggs on the market with a bright yolk and two yolks, enriched with selenium or iodine. Also, when feeding laying hens with special mixtures of spices, you can get the original taste of eggs.
When choosing chicken eggs in a store, buyers usually focus on the expiration date and cost of the product. Few people think about product labeling, although it is by this labeling that one can determine the freshness and beneficial properties of the product. There are also folk ways of determining the quality of eggs - by lowering them into water or spinning them on a horizontal surface. But such methods are not always convenient and accessible, especially when choosing products in a store. And knowing the decoding of the code printed on the product, you can easily evaluate and select the highest quality and freshest eggs from the entire range presented.
Classification
Depending on the time that has passed since the eggs were laid, they are divided into two groups: dietary and table. Dietary products are marked with a red stamp with the letter “D”.
A red stamp is applied to the diet egg
It is assumed that such eggs are fresh, and no more than seven days have passed since they were laid. Dietary products are subject to certain requirements according to GOST: they must have a uniformly colored yolk, dense white, and an air gap of no more than 4 mm. Only single dots or stripes are allowed on the shell. It is unlikely that an ordinary consumer will be able to assess the compliance of a particular product with all these requirements - such an assessment is carried out selectively and in a specialized laboratory.
Diet eggs are difficult to find in modern stores. After all, quite a lot of time is spent on collecting, sorting, packaging, distributing to warehouses and transporting products, so stores prefer not to deal with such goods and buy table eggs. Such products are marked with a blue stamp and must be sold within 25 days. Thus, a newly laid egg during the first week of storage is classified as dietary. Starting from the second week, it does not become spoiled (subject to storage conditions), but goes into the canteen category.
A table egg can be identified by a blue stamp
Eggs classified as table eggs can be stored in the refrigerator for up to 90 days. Unlike dietary products, products in this category allow mobility of the yolk, low protein density and an air gap of more than 4 mm (usually 5–9 mm). If there are spots or stripes on the shell, they should not occupy more than 12.5% of the total surface area.
Gradation by size
The main parameter in classification is mass. Based on this feature, the following categories of chicken eggs are distinguished:
- 1. The first includes products weighing 55-64.9 g.
- 2. The second includes products weighing 45-54.9 g.
- 3. The third category includes eggs with the smallest weight - from 35 to 44.9 g.
There is also a group called “selected” with a mass of 65 to 74.9 g. Such products are marked with the letter “O”. A table egg classified in this category will be marked with a blue “C0” stamp.
Product units weighing more than 75 g are marked with the letter “B” on the shell and/or packaging, which means the highest category.
In accordance with GOST 31654–2012 “Chicken eggs for food. Technical Specifications”, there may be no marking on the shell of each egg if the necessary information is available on the container in which the products are supplied. But this is only allowed if it cannot be opened without visible damage. Such restrictions are necessary to prevent misgrading or substitution of product units between different packages.
If the package can be easily opened and closed without damaging the label, then each egg should be stamped with the category.
If products in a store are displayed in such containers, then each egg must be labeled
Composition and beneficial properties of the product
Chicken eggs become an essential part of the diet for many people, as they contain a large amount of essential nutrients, vitamins and microelements.
But modern science often makes consumers doubt the benefits of such products and even begins to convince them that their use is harmful to health. In order to objectively assess the need for eggs in the daily diet, you need to consider the chemical composition of the product.
Each egg consists of a shell, white and yolk, and these, in turn, contain proteins, fats, carbohydrates, and water. But the ratio by weight of these components varies depending on the breed of chickens, diet, age, region and conditions of keeping hens. Younger hens usually lay small testicles, which are classified as category 3 or 2.
Each unit includes the following components:
- 1. Vitamins and minerals. Chicken eggs contain B vitamins, calcium, iron, phosphorus, magnesium, potassium, zinc. Depending on the chickens' nutrition, the product may contain additional beneficial substances. Some manufacturers mark on the packaging that their products are enriched with iodine or selenium. This means that the specified components were additionally introduced into the diet of laying hens so that the laid eggs had an increased number of beneficial properties.
- 2. Proteins. Each egg contains proteins such as albumin, transferrin, lysozyme, and globulin. These components have various beneficial properties, in particular antibacterial. Egg white is highly valued by athletes as it provides protein that is easily digestible.
- 3. Fatty acids. The yolk contains linoleic and linolenic, as well as oleic, palmitic, and stearic acids. It also contains a component such as choline, which is one of the components of cell membranes. It helps improve memory, regulate insulin levels, synthesize amino acids and remove toxins from the body.
Possible harm to eggs
Recently, disputes have not subsided between supporters of adding eggs to all possible dishes and their opponents, who claim that eating such food is harmful to health. Those who have a negative attitude towards the use of such products in nutrition cite the following arguments:
- 1. Eggs contain cholesterol. According to researchers, it promotes the formation of blood clots and clogging of blood vessels. But recently the media began to report that there are two types of cholesterol - good and bad. Moreover, the one that is absorbed from food does not cause any harm. And yet, for many people, the presence of cholesterol in a product becomes a reason to refuse such food.
- 2. Consumption of such products may cause salmonellosis. Scientists have long proven that if certain principles are followed, the risk of getting sick is minimized. These rules are as follows: eggs with damaged shells should not be consumed; it is advisable to rinse them under running water before cooking; you should refuse to eat the raw product and be sure to heat treat it.
- 3. The product has a high calorie content. Per 100 g there are approximately 150–160 kcal. In certain cases, high calorie content is considered a positive property of eggs. Athletes who are interested in gaining mass during certain periods of training include their consumption in their daily menu. However, like any other product, you should not abuse them and consume ten a day. In addition, as you can see from the following table, the calorie content of chicken eggs is not the highest in comparison with duck, goose or turkey eggs.
Comparison of caloric content of eggs depending on the type of bird.