The production of each product necessitates chemical, physical and microbiological control based on the ever-widening development of science in order to ensure that the necessary information is always available in the production process. Without this, it is now impossible to create a new product.
Thus, for the introduction of technological lines and the entire new products a number of quality control measures are required, which must be applied without fail to constantly meet the ever-increasing requirements for product quality.
Although chicken eggs are sold through trade, eggs of other types of poultry may be sold. By size, shape, shell color, it is not difficult to recognize goose and turkey eggs. Of particular importance is the separation of duck and chicken eggs, because very often duck eggs are contaminated with salmonella.
On average, chicken eggs weigh 50-60 g, the shell is white or brown, on which the pores in most cases can be seen with the naked eye. In contrast to chicken eggs, the mass of duck eggs is 60-70 g, the shell has a greenish tint, smooth, shiny, it seems that it is covered with an oil coating, the pores on the shell are not visible to the naked eye. However, these differences are not always clear enough to distinguish between chicken and duck eggs on the basis of objective features. However, there are differences in the composition of the shell (mostly not related to feeding). By method
Wettzel (1967) using photometry determine the magnesium content in the shell. The result obtained makes it possible to distinguish between duck and chicken eggs. A method has been developed for the determination of duck and chicken eggs based on a serological analysis of the protein composition. With such an analysis, it is possible to achieve results even if the egg is subjected to a slight heat treatment.
The translucence described above allows you to determine the size of the pug, the state of the protein and yolk.
Egg quality control includes the determination of the fact of egg washing. When translucent with ultraviolet rays, the shell fluoresces in red and blue. Gray spots can be observed on it, from which pollution has been washed away. Quite effectively, you can use the method of immersing eggs in a solution of paints, when the colored cuticle can be separated from the lime shell, if it has not been washed off before washing (in this case, this place is not painted).
After breaking the egg, its contents are evaluated organoleptically. Determine the indicators of raw eggs: color, smell, consistency; after boiling soft-boiled eggs without adding salt - compliance of taste, color and smell with the requirements of the standard or any deviations from them are noted.
Specific gravity is one of the characteristic physical properties eggs, the knowledge of which serves as an additional indicator in determining the quality. The resulting ratio between volume and mass indicates a change in the quality indicators of the egg. The specific gravity is determined as follows: the egg is weighed to the nearest hundredth of a gram, its volume is determined based on the volume of water displaced, and the weight of the egg is divided by its volume. The specific gravity of the protein or yolk is determined after homogenization of the analyzed material using a specific gravity device.
The age of an egg can be judged by the yolk and protein index. The contents of the egg are poured onto a flat glass. The yolk of a fresh egg retains its round appearance, does not spill, and is only surrounded by a protein in a small area, in which it is possible to clearly distinguish between a dense and liquid layer. The egg index is determined by the height (altimeter) and width (caliper) of the egg spilled on the glass. To calculate the index, the following ratios are used: yolk index - height: width; protein index - dense protein height: average width.
For a better estimate, the measurement result is multiplied by 10,000.
The pH value of protein and yolk is determined separately.
The change in the contents of the egg can be followed based on the determination of the refractive index. The actual refractive index is affected by many factors (water content, specific gravity, egg age, etc.). The resulting coefficient can only be used to compare eggs of the same species and age. The measurement is made with an Avve refractometer using a sodium lamp.
Determination of the color of the yolk in some cases is also necessary to assess the quality of the egg.
When analyzing the quality of egg products (melange, egg powder), organoleptic indicators are determined.
The sample is regulated by the regulations of the current standards. For laboratory analysis, before conducting an organoleptic analysis, an aqueous emulsion is prepared from the sample taken. To do this, add 60 ml of water to 20 g of egg powder, dissolve everything and leave it alone for 15 minutes. Without adding fat, the emulsion is fried over low heat burners. The fried sample after cooling to room temperature is analyzed. It is necessary to determine whether there are deviations in the production of the powder: its processing (pasteurization) and manufacturing (spraying).
After pasteurization of the liquid egg mass, it is necessary to control the colloidal state. When deviating from the processing mode, a certain coagulation of the product may occur. This pasteurization defect can be determined by comparing the viscosity values before and after heat treatment. It is advisable to measure the viscosity of liquid egg products with a rotational viscometer. For the same purpose, you can use the determination of the content of soluble dry matter.
The solubility index of egg powder can be used to detect a manufacturing defect. In order to obtain more reliable results, an original method was developed: prepare a solution of egg powder with a known powder content, determine the refractive index with a refractometer and use it to determine the amount of dissolved dry matter. Based on the obtained indicator, the percentage of dissolved egg powder is calculated.
Efficiency of pasteurization of egg mass, except for technological control, it is advisable to check in other ways, for example, using an alpha-amylase test (heat treatment damages the amylase contained in the whole egg). Therefore, if the heat treatment was appropriate (at least 64°C for 2.5 minutes), no amylase could be isolated from the pasteurized sample. This method of control is very simple and relies on the fact that alpha-amylase decomposes starch, which does not give the characteristic starch-iodide color reaction.
During storage in melange, undesirable chemical and microbiological changes may occur in egg powder, resulting in the breakdown of proteins and fats. One can get an idea about the processes of oxidation of the fatty phase of melange or egg powder by determining the acid and peroxide numbers.
Egg spoilage can occur from a purely fermentative process without the presence of bacteria, or from penetration of microorganisms through the shell. The fact of damage is established by transillumination. After breaking the eggs, the internal contents are analyzed. Microbiological analysis is usually carried out in accordance with the methods of microbiological control of other food products. Sowing is carried out on an elective or selective nutrient medium from the yolk or protein, as well as from a mixture of them.
The most common infection of the egg shell in the
nom mixed microflora of enterobacteria: Pseudomonas,
Alcaligenes, Aeromonas, Micrococcus, Bacillus. Germs of bacteria pass through the pores of the shell and microcracks, and also get inside as a result of improper processing (unskilled washing, damage to the cuticle). Here begins the first reproduction of microorganisms, as a result of which Gram-negative bacteria mainly multiply. Which populations, which putrefactive bacteria will develop, depends on storage conditions, and above all on temperature.
At temperatures up to 30 ° C, Pseu
domonas, and the faster the lower the temperature. At high temperature Acinetobacter multiplies, and at a temperature of about 37 ° C, Coli bacteria will become the dominant flora.
During storage, water activity decreases, which prevents the development of gram-negative bacteria, so again the more resistant Micrococcus come to the fore. However, the development of bacteria does not always occur, because the bactericidal substances of the protein (for example, conalbumin) inhibit the growth of gram-negative bacteria.
Together with temperature, the growth of bacteria is affected by humidity and the storage environment. So, with longer storage, the egg white blurs and the yolk comes into contact with the shell. At the point of contact, micro-organisms grow particularly easily or mold forms.
All types of microbial decomposition lead to characteristic
changes in the protein that are easy to see when translucent
or breaking an egg.
Green rot is caused by microbes of the Rseudomonas group. In this case, the protein strongly fluoresces under ultraviolet rays.
Red decay is noticeable when translucent in the form of a red color. In most cases, coli bacteria or other types of enterobacteria can be isolated from these eggs.
White rot is caused by Micrococcus. Protein and yolk are mixed together.
Proteolytic bacteria that produce hydrogen sulfide form black rot. Most often there are Proteus groups.
Lipolytic species (Pseudomonas and some Bacillus) produce characteristic aromatic substances.
In some cases, various pathogenic bacteria also penetrate the eggs.
In this case, only those pathogens that occur in eggs and are of public interest are considered.
Often eggs are infected with various salmonella. Salmonella sgallindrum or other species are sometimes found in chicken eggs, while Salmonella typhimurium is more commonly found in duck and goose eggs. Although the human body is insensitive to the species S. gallina, raw eggs should not contain this type of Salmonella (in mayonnaise, creams, etc.). Ignoring sanitary and hygienic requirements can lead to serious consequences when infected eggs, after being scanned on the farm, are sent for sale as food eggs. In such eggs, among the microflora, there may be salmonella that causes human disease.
Countless scientific reports indicate that duck eggs can lead to food poisoning.
Based on studies conducted in Hungary, it was found that Salmonella from the surface of the egg shell can penetrate into the yolk within 24 hours. In many countries it is forbidden to use duck eggs as food product. Heat treatment at elevated temperatures does not guarantee against poisoning.
According to observations, even when eating fried eggs from duck eggs, food poisoning is possible.
Egg products (melange, egg powder) may also contain various microorganisms. The bacteriological purity of these products must be checked after their production has been completed.
The avian tuberculosis bacillus can be found in the egg. It causes disease in humans, but such publications are known that unambiguously confirm human disease from a bacillus - Mycobacterium avium.
The disease of avian tuberculosis in laying hens in Hungary occurs only in livestock in a personal household plot.
It has been established that tuberculosis bacteria are often found in the initial stage of an acute disease in the absence of pathological changes in the ovary. With the chronic nature of the disease, egg production decreases or stops completely, so the penetration of the pathogen into the egg at this time is very rare. Eggs from TB-sick laying hens, if eaten raw, can infect the consumer.
In order to prevent infection of eggs from a sick population of chickens, it is forbidden to sell such eggs.
For the analysis of melange products, 5% of the product batch is taken. For microbiological analysis take a mixed sample (250 g).
According to the law in Russia, eggs are supposed to be sold not by weight, but by the piece. Right at the poultry farm, after laying, the eggs are sorted, dividing them into several weight categories, then they are labeled and packaged. So find out approximate weight eggs can by marking, which is either applied to the surface of the shell, or written on the packaging and price tag. The full list of possible categories is shown in the table below.
| Marking | Weight, g | Category | Weight tolerance, g | |
|---|---|---|---|---|
| from | before | |||
| 40 | Third | 35 | 45 | |
| 50 | Second | 45 | 55 | |
| 60 | First | 55 | 65 | |
| 70 | selected | 65 | 75 | |
| 80 | Higher | 75 | - | |
What do the numbers and letters mean
Numbers 1 , 2 , 3 and letters ABOUT(choice), IN(highest) indicate the weight category of the eggs.
Letter WITH(table) means an egg with a long shelf life suitable for human consumption.
Letter D(dietary) means a high quality fresh egg, which after 7 days of storage (from the moment of laying) will lose its advantages and move to the rank of a regular table egg.
What kind of eggs to buy for recipes?
In domestic culinary recipes, it is customary to use the smallest chicken eggs of the third category weighing 40 grams.
Why are eggs sold by the piece and not by weight?
In Russia, this is prescribed by law. And there are plenty of that.
I weighed the purchased eggs, it turned out that they weigh less. Are we being deceived?
Without a doubt, poultry farms can deceive customers by labeling dishonestly. But, only a special check from Rospotrebnadzor can prove this. However, usually the weight does not match because during storage, the eggs lose weight very quickly due to the evaporation of moisture through the shell.
Do not eat cracked eggs. When buying, feel free to look for packages without cracked eggs.
If you do not trust the store or poultry farm, then check the weight of the eggs right in the store on the control scales.
Wash them with soap before cooking.
Weight of yolk, protein and shell
Most of the eggs are protein. At long-term storage some of the water from the protein evaporates, as a result of which the total weight of the egg decreases. Often lost weight can be replenished by topping up with protein clean water, but this is only in the case when, according to the recipe, the protein or the whole egg must be shaken.
| Code | Category | General Weight, g | Weight of components, g | ||
|---|---|---|---|---|---|
| yolk | protein | shell | |||
| Third | 40 | 12 | 23 | 5 | |
| Second | 50 | 16 | 29 | 6 | |
| First | 60 | 19 | 34 | 7 | |
| selected | 70 | 22 | 40 | 8 | |
| Higher | 80 | 25 | 46 | 10 | |
Weight of imported eggs by marking
| Marking | Category | Weight, g | Russian analogue | |||
|---|---|---|---|---|---|---|
| from | before | Category | Marking | |||
| Small | less than 53 | Second Third | ||||
| Medium | 53 | 63 | First | |||
| large | 63 | 73 | selected | |||
| Very Large | over 73 | Higher | ||||
Why eggs are not sold by weight, but by the piece
1. It is convenient to sell in ready-made packages of several pieces, but inconvenient by weight.
2. The weight of eggs during storage is significantly reduced due to the evaporation of moisture through the shell. In practice, selling by weight will lead to the fact that the trading network will buy from the poultry farm, for example, 1000 kg of eggs, and sell only 950 kg. The weight loss of eggs due to evaporation will have to be included in the sales margin, which will increase the price.
3. Eggs are a fragile product, the more operations are performed with them, the more eggs will break and crack. When weighing during the sale, the amount of broken goods will increase, which will also negatively affect both the price and quality.
4. Eggs cannot be sold together with other products due to the possibility of contamination of neighboring products with salmanella, therefore, in order to weigh the eggs, the store will have to open a special department for selling eggs and an additional workplace seller. In such conditions, the price of eggs will skyrocket to indecent values, and small shops will not be able to afford the sale of this product at all.
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Introduction
The purpose of our work is to determine the strength of a chicken egg (with different shell colors: white and brown), for which physical methods were used, chemical experiments were carried out.
1. Study the literature on the research topic.
2. Study the structure of the egg shell.
3. Learn to determine the mass, density, strength of eggs.
The relevance of this topic is that it reveals approaches to solving practical problems that arise in everyday life. Chicken eggs are a nutritious and healthy food. Biologically complete egg protein in its composition approaches the optimal need of the human body for amino acids. Bread and milk, eggs and meat, vegetables and fish are traditional foodstuffs for Russians. And eggs throughout the history of mankind are part of natural food.
Today, nutritionists recommend that a healthy person eat 1-2 eggs a day. One chicken egg at the same time satisfies the daily requirement of an adult in protein by 10%, fat - 7%, phospholipids (lecithin) - more than 50%, vitamins - from 5 to 100%, iodine - 15-20%, zinc and copper - 8-10%, selenium - up to 50%.
Among the characteristic criteria for the quality of eggs in the first place is the mass, the larger the egg, the higher its nutritional value. The mass of eggs varies widely, but most often from 45 to 65 g.
Strength is the main quality of the egg shell. The shell is a calcareous shell, which consists of two layers: the inner one, which makes up one third of the shell, and the outer one. Its thickness is 0.2-0.4 mm with a decrease at the blunt end. The shell protects the contents of the egg from mechanical damage, microbial contamination and moisture evaporation. The egg shell contains calcium carbonate (93.5%) and magnesium (1.4%), calcium and magnesium phosphate (0.8%), a small amount of organic matter.
The color of the shell depends on the type and breed of the bird. In egg breeds, it is white, in meat breeds it has various shades - from straw yellow to brown. In the work, we will find out whether color affects the strength of the shell.
Research hypothesis:
The color of the eggs affects the strength of the shell;
An egg with a brown shell is more durable, because. contains more calcium carbonate than a white-shelled egg.
Location of the study: the city of Izhevsk.
Object of study: chicken eggs.
Breeds of chickens and their modern distribution
Edible eggs are obtained mainly from chickens of egg breeds, in a smaller volume - from meat - egg and meat chickens. Broilers are the main source of poultry meat. Modern poultry farms are full-fledged industries engaged in both poultry cultivation and the manufacture of semi-finished products from its meat. The main processes are automated. For keeping birds, a cage battery is most often used.
The main features underlying the classification of breeds include the direction of their use by humans, live weight, egg production, plumage color, crest shape, size and color of eggs, safety of young and adult bird etc.
All breeds are divided into the following main groups according to the direction of use:
broilers (have low egg production, but high body weight and palatability),
laying hens (have high egg production, but often low palatability, sometimes low body weight),
meat - egg (as a rule, they have medium egg production and medium or high body weight, as well as good taste),
fighting (individuals are massive, elongated, the direction is created for cockfights),
decorative (have unusual decorative properties - dwarfism, special colors, etc.).
In accordance with this classification, all breeds of chickens can be grouped as follows:
meat chickens - brahma, cochinchin, etc.
egg chickens - leghorn, Russian white, rhodonite-2, etc.
meat and egg chickens - Orpington, Faverolle, Wyandot, Australorp, Amrox, Kuchinsky Jubilee, Moscow White, Moscow, New Hampshire, Rhode Island, etc.
fighting chickens - azil, English fighting, Indian black, Malay, Moscow fighting, etc.
ornamental chickens - seabright, bantam, dwarf wyandot, white-crested Dutch black, dwarf cochin, curly, paduan, silk, etc.
Have you ever wondered what determines the color of eggs in a chicken? After all, there are shells of different colors, both white and brown shades. What is it - different varieties of eggs or a sign of quality? Let's try to figure out what affects the pigmentation of the shell and yolk.
Among the inhabitants there is an opinion that the composition of brown eggs is more natural, so to speak, homemade. In fact, the quality of the product produced by a laying hen depends on many factors. But the color does not affect the taste or quality of the eggs. And vice versa, the conditions of keeping and feeding the chicken do not affect the color of the food prepared from it. And yet, what determines the different color of chicken eggs?
Factor 1. Breed
So, the color of the shell in the products that are carried by domestic and industrial chickens depends on the breed of the bird. At the same time, the ability to carry eggs of a certain color is laid genetically. That is, the same chicken throughout its life produces fruits with a shell of a certain color. And such a pattern is often observed: the color of the shell depends on the color of the feathers.
So, laying hens with white feathers are mostly carried in white, but pockmarked and golden ones are brown. To know for sure what color your hen's eggs will be, take a closer look at the earlobe. If it is white, then the eggs will have the same color. In chickens with a red ear, the color of the shell will be brown.
For each breed of chickens, certain color characteristics are inherent. So, Leghorns and Russian Whites have white plumage, and their shells are of the same color. By the way, these breeds are distinguished by the greatest egg production. That is why white-shell protein products predominate in shops and markets.
In the household, they prefer to have birds that are capable of both carrying eggs and confidently gaining weight. Such breeds are mostly brown in color, respectively, and their eggs acquire the same color. These include Dominican laying hens, Rhode Island, Orpington and other meat and egg chickens.
For some reason, people have the opinion that since domestic eggs have a brown tint, this is a sign of their naturalness. One way or another, this stereotype is based on the subconscious, and has nothing to do with common sense. But farmers are breeding new breeds that lay well and produce brown-colored eggs in order to win the favor of the buyer.
By the way, we are all used to seeing chicken products with white and brown shells on our table. And in South America There is a specific breed of hens that lays bluish-green eggs. The chickens themselves look very original: they do not have tails, but feather decorations have formed on their heads in the form of mustaches and beards. The breed is called "Araucana" - in honor of the name of the tribe of Indians who bred such chickens.
In the middle of the last century, testicles from Araucan chickens gained popularity, but why? Among Americans, an opinion has appeared that the protein product of these outlandish birds contains several times more useful substances, and the cholesterol level, on the contrary, is much lower than in ordinary eggs. However, later studies have shown that the chemical composition of such eggs is no different from others, and the hype has passed.
Factor 2. Environment
The intensity of the color of the shell varies from pale, creamy shades to rich reddish. What does it depend on? Shell color is influenced by various external factors: air temperature, stressful situations, diseases. The brownish color comes from a pigment called protoporphyrin. It is found in hemoglobin and various vitamins, and is quite common in many forms of wildlife.
The more time it takes for the fetus to pass through the oviduct, the more intensely it stains. This is because the porphyrin acts on the membrane longer. Also, the intensity of the color depends on the laying period: the first ones usually turn out darker.
Scientific studies have proven that the color pigment that affects the formation of color is located in the cells of the uterine organ of the laying hen. Therefore, the color of the shell is determined even at the initial stages of egg formation.
What affects the color of the yolk?
The color of egg yolk sometimes excites both beginners and experienced housewives. Let's see why in one egg the yolks are pale yellow, in the other they have a bright saturated hue, and in the third there may be a poisonous orange yolk.
The color of the yolk is a consequence of the influence of pigments belonging to the group of carotenoids. Carotenoids are natural pigments that give color to plants and fruits. However, not all types of pigment affect the color of the yolk. For example, beta-carotene, which makes carrots orange, will not affect the color of the yolk. But the pigments lutein or xanthophyll are able to achieve the bright color of egg yolk.
The color of the yolk depends on the diet of the bird. If the chicken eats foods rich in yellow pigment, then the yolk will have a richer yellow or orange hue. This effect is given by corn of bright yellow varieties, grass meal. If you feed chickens with pale varieties of corn and alfalfa, then the tint of the yolk will be pale yellow. When feeding with colorless food, the yolk will also have a barely noticeable yellow tint.
This indicator is not a sign of freshness, naturalness or nutritional value egg product. But producers of eggs for sale are trying to feed hens with brightly colored food to make the product look more attractive to the buyer. Interesting fact: for some reason, the yolk contains more protein than the protein itself, so the benefits of the yolk are not measured by the shade.
Research methodology
The mass fraction of the shell is an indirect indicator of its thickness and strength. To determine this indicator, the egg and the shell (without the shell film) are weighed with an accuracy of 0.1 g, and then the ratio (in%) is calculated using the formula, where is a dimensionless value equal to the ratio of the mass of the shell to the mass of the egg (we took this formula from a chemistry textbook for grade 8).
2. Shell strength is the most important indicator of an egg. The shell is crushed until a crack appears.
Take raw eggs, carefully drill holes at the ends (using a needle) and pour the contents of the eggs out through them. Glue a sticky tape to the side surface of each egg so that it runs along its equator, dividing the egg into two hemispheres - with blunt and sharp ends. The adhesive tape is needed so that the hemispheres do not crack when we separate them from one another. Then you need to take a scalpel and cut the empty eggs along the middle line of the adhesive tape. You will get empty egg hemispheres. Lay them on a flat table surface with the poles up (cut edges down) so that they form a square with a side of 15 cm.
And now carefully put the weights. The data obtained were entered in table 1. Then they found the mass that the egg can withstand in a horizontal position, which will make it possible to find out which egg is stronger.
3. Composition of calcium carbonate in the shell. To do this, we need an egg with a brown and white shell, acetic acid and a glass cup (so that the egg fits in it).
We put the egg in a glass and fill this glass with vinegar (9%). In this form, we leave the whole composition for several days.
The calcium carbonate in the egg shell must react with acetic acid to form a solution of calcium acetate, and the protein and yolk are denatured (they change the shape of protein molecules) under the influence of an acidic environment. We will observe the changes that occur with the shell (brown, white), which shell will dissolve faster.
4. Determination of the density of an irregularly shaped body (chicken egg).
Density is determined by the formula, ρ = m / V, which we studied in the 7th grade in physics lessons. The mass can be determined by weighing on a balance, and the volume can be found as the difference between the volume of water in the beaker with and without the egg.
The volume is calculated by the formula V eggs \u003d V (water with an egg) -V (water).
Density is determined by the formula ρ=m/V.
4. Research results and their analysis
1. The mass fraction of the shell is an indirect indicator of its thickness and strength.
To calculate the mass fraction of the shell, we took one egg, weighed it on a scale, and got the following result: an egg with a white shell - 55 g, with a brown one - 49 g. Then we broke and poured the contents into a cup. The shell was weighed, it was obtained that the weight of the white shell was 6 g, and that of the brown shell was 7 g.
We did the calculation:
For white-shelled eggs: 6 grams is 11% of the total weight of the egg.
For brown-shelled eggs: 6 grams is 12% of the total weight of the egg.
The mass fraction of the brown shell is greater than the mass fraction of the white shell.
2. The results of determining the strength of eggs with brown and white shells were entered in the table.
Table 1. Determination of the strength of the egg shell.
The brown shell withstood a mass of weights of 1 kg 500 g and crushed, which is 220 g more than the white shell withstood.
3. The laying was carried out on January 5 at 13.40. After 19 hours, the egg shell was examined, the changes that occur with the shell (brown, white) in vinegar were observed, which shell would dissolve faster. The brown shell completely dissolved after 27 hours, and with the white shell after 23 hours. This experience proves our hypothesis that brown-shelled eggs are more durable, because contains more calcium carbonate than a white-shelled egg.
4. To determine the density, it is necessary to divide the mass by the volume. The mass can be determined by weighing on a balance, and the volume can be found as the difference between the volume of water in the beaker with and without the egg.
Table 2. Determination of egg density.
The volume was calculated by the formula (water)
Density was determined by the formula
5. Conclusions:
1. The larger the chicken eggs, the weaker their shell.
2. Brown chicken eggs are much stronger than those with white shells. The shells of brown eggs are slightly thicker, so they have a slightly longer shelf life. They are less susceptible to damage.
3. The thickness of the shell is related to the density of the eggs. The thicker the shell, the greater the density of the egg.
5. Eggs are healthy and nutritious. On average, a chicken egg contains 80 kilocalories. In terms of calories, it is equivalent to a medium-sized apple, half a banana, 100 grams of beef tongue or chicken legs. In addition, eggs contain valuable vitamins, minerals and protein. Eating eggs not only provides energy, but also has a positive effect on the condition of hair, vision and the whole body.
6. Cholesterol in eggs is not as dangerous as it is commonly believed - it is found only in the yolk and is balanced by lecithin (a substance also found in eggs and helping to process cholesterol and fats).
7. Eating raw eggs is dangerous. Delicious eggnog can bring unpleasant consequences in the form of salmonellosis. A dangerous bacterium is often found in raw eggs and dies during heat treatment. It is also important to thoroughly wash the eggs and prevent germs from the surface of the shell from getting into the egg mass.
8. On average, a laying hen produces approximately 250 - 300 eggs per year. It takes about a day to lay one egg.
9. White eggs are just as healthy as brown ones. Contrary to the widespread myth about the exceptional benefits and taste of brown eggs compared to white ones, the latter are no worse. The difference lies only in the breed of chickens that carry these same eggs. The color of the shell depends on the color of the laying hen - the pockmarked eggs are brown and beige, and the white hens lay white eggs. The color of the yolk depends only on the chicken's diet.
10. Diet eggs are healthier than table eggs. The classification of eggs into dietary and table eggs depends on their freshness. Eggs stored at a positive temperature for no more than 7 days after laying are considered dietary. Canteens can be stored up to 25 days. Dietary, in turn, are divided into selected (from 65 grams) and eggs of I (at least 55 grams) and II (at least 45 grams) categories.
11. Eggs should not be stored near strong-smelling foods. Thanks to the porous shell, they easily absorb odors.
12. The longer the egg has been cooked, the harder it is to digest. A hard-boiled egg will be digested by the body in about three hours. That is why it is better not to eat hard-boiled eggs before going to bed.
6. Conclusion
In what follows, we assume that will be investigated:
1. Is cholesterol in eggs as dangerous as it is commonly believed, or is it found only in the yolk and is balanced by lecithin (a substance also found in eggs and helping to process cholesterol and fats).
2. Is it possible to store eggs next to strong-smelling foods. Thanks to the porous shell, they easily absorb odors.
3. How to determine the freshness of an egg? True or myth that it can be lowered into a bowl of cold water. The fresher the egg, the smaller its air chamber, which means the egg will sink. At the same time, a stale egg will float to the surface, such an egg is not advisable to eat.
7. List of used literature:
1. Agafonychev, V. Egg products: global trends and Russian market/ V. Agafonychev // Poultry farming. 2007. - No. 7. - S. 3-4.
2. Anatomy of pets: textbook. allowance / ed. I. V. Khrustaleva. M.: Kolos, 2000. - S. 662-664.
3. Bessarabov, B. F. Poultry farming and technology for the production of eggs and poultry meat: tutorial/ B. F. Bessarabov, E. I. Bondarev, T. A. Stollyar. St. Petersburg: Publishing house "Lan", 2005. - 352 p.
4. Bobyleva, G. A. The state of poultry farming in Russia / G. A. Bobyleva // Fisinin, V. I. Geese of the Urals / V. I. Fisinin, S. F. Sukhanova, A. G. Makhalov. Kurgan: Publishing House of OJSC PK Zauralie, 2008. - S. 3-9.
5. Bogolyubsky, S. I. Methods for improving the quality of eggs / S. I. Bogolyubsky, P. P. Tsarenko // Improving the quality of food eggs. -M.: Kolos, 1976. S. 40-50.
6. Vrakin, V. F. Anatomy and histology poultry/ V. F. Vrakin, M. V. Sidorova. -M.: Kolos, 1984. S. 197-210.
7. Golikov, A. N. Physiology of farm animals / A. N. Golikov. -M.: VO Agropromizdat, 1991. 432 p.
8. Kiselev, L. Yu. Line breeds and crosses of agricultural poultry / L. Yu. Kiselev, V. N. Fateev. M.: Kolos, 1983.- 160 p.
9. Kochish, I. I. What is the most promising hemlock? / I. I. Kochish // Poultry farming. 1999. - No. 4. - S. 24-25.
10. Kochish, I. I. Poultry farming: textbook / I. I. Kochish, M. G. Petrash, S. B. Smirnov. M.: Kolos, 2003. - 407 p.
11. Kravets, G. White and brown crosses: which are more profitable? / G. Kravets // Livestock in Russia. 2006. - No. 12. - S. 13-14.
12. Orlov, M. V. Breeding chickens / M. V. Orlov, E. K. Silin. M.: Kolos, 1981.-269 p.
13. Fisinin, V. I. Egg production today / V. I. Fisinin // Poultry farming. 2007. - No. 7. - S. 2.
14. Hunton, P. A revolution in the production of eggs: brown versus white / P. Hunton // Poultry. 1993. - No. 4. - S. 34-37.
15. Tsarenko, P. Evolution of the quality of a chicken egg / P. Tsarenko, L. Vasilyeva // Poultry farming. 2009. - No. 1. - S. 21-22
16. Stele, A. JI. Chicken egg: yesterday, today, tomorrow / A. JI. Stele. - M.: Agrobusinesscenter, 2004. - 196 p.
17. Eidrigevich, E. V. Interior of farm animals / E. V. Eidrigevich, V. V. Raevskaya. — M.: Kolos, 1966. 208 p.
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