Characteristics and packaging of hottest eggs I

Egg properties and packaging (I)

1 egg composition and properties

1.1.1 the structural model of egg is shown in figure (11-1)

eggs are composed of the following parts to improve the ability of product creation and development:

1.1.2 physical composition of eggs

generally goose eggs are the largest, fire eggs are the second, pigeon eggs and quail eggs are the smallest. However, its composition also varies with feed and season

(L) eggshell and eggshell membrane

eggshell is an inorganic porous material, which is closely connected with two layers of eggshell membrane. Most of its components are inorganic, organic matter only contains 4.5% - 5.5%, and water content is 1.5%. The rest are inorganic. The main components are caco3,93.7%, MgCO3 1.39%, p205, 0.76% O. there are two kinds of eggshell pigments: white and light brown. The main component is frotoporpbvin. Eggshell and membrane proteins are keratinocytes. It has strong decomposition resistance to bacteria. The thickness of the eggshell is about 1/100mm. The pores on the eggshell can allow water vapor, gas and bacteria to enter and leave. Its permeability is related to the number of pores on the eggshell. Generally speaking, the eggshell has a large number of pores at the blunt end, which has a larger permeability, and a small number of pores at the tip, which has a smaller permeability. The thickness of eggshell is related to composition and feed. If Ca in the feed is insufficient, the eggshell has a mutual coordination relationship

the thickness, composition, strength, number of pores and permeability of egg shell are greatly related to the processing, storage and incubation of eggs, which must be paid attention to

(2) protein

according to figure 11-l, proteins are divided into outer thin protein, thick protein and inner thin protein. Its content is about 1/4 of the outer protein, about 50% of the thick protein, and about 6O% of the thick protein, which is used as the inner thin protein. The solid content of ovalbumin is about 12%, most of which is protein and exists in aqueous solution

protein composition: moisture 85% - 88%, average 87%, protein 10% - 13%, average 12%, ash 0.7%, levulose 0.3% - 0.5%, fat, yolk, cholesterol microdisk. Its 100g protein contains 70% egg protein, 9% milk protein, a small amount of globulin, less sugar, and exists in combination with protein. The mineral components include potassium, sodium, magnesium, and this paper briefly introduces the testing function of the spring fatigue tester. There are many vitamins such as phosphorus. It also contains B1

protein is soluble in water and has foaming property. Stirring in the air will produce stable foam. It is often used in cake making

the freshness of eggs can be known from the changes of phosphorus in eggs. During storage, the inorganic phosphorus in eggs increases, and the change angle of fresh eggs is also different. After storage at 14 ℃ for 8 months, the inorganic phosphorus in eggs increases from 0.04-0.1 mg% to 3. The slight difference is only in the subdivision specification of products produced 45-6.46mg%, organic phosphorus, phosphorus in egg yolk phospholipids are free to move to protein

the freshness of eggs is also related to sulfur. The more sulfur in eggs, the lower the freshness. When eggs are rotten, a large amount of H2S occurs. This is caused by the decomposition of organic sulfur. If the sulfur yellow in the egg is determined, the freshness of the egg can also be known

after boiling, there is a layer of green at the contact between protein and egg yolk, which is iron sulfide. This is formed by the combination of hydrogen sulfide in protein and iron in egg yolk. Silver turns black when it contacts with eggs and turns into silver sulfide

vitamins in eggs will change during processing and storage. Details are listed in table 11-3

it can be seen that several of the protein increase during storage, and its content also varies with the chicken feed. The average content of vitamins in protein and egg yolk is 2.7ug/g, g/g

(3) egg yolk and egg yolk film

the egg yolk is located in the center of the egg and is wrapped by a layer of egg yolk film. This film is extremely thin. The egg yolk film of about an egg weighs only 6o-80mg according to the determination in the dry matter. It has permeability, and the substances in egg yolk and egg protein move from egg yolk to egg protein, which are often found during storage

the egg yolk is rich in protein and has better nutrition. The egg yolk can be divided into white egg yolk and yellow egg yolk. It is difficult to separate the fresh egg yolk. When the egg yolk hardens, it may be separated by different colors. The content of white egg yolk is small, accounting for only 3% and 4% of the whole egg yolk, and the composition of the two is different. It can be seen from table 11-4

under the microscope, the globule of protein in yellow egg yolk is larger than that in white egg yolk. This is the biggest difference

the composition of egg yolk is roughly as follows: moisture 49.5%, protein 15,9%, lipid 33.3%, pigment 0.05%, ash 1.5%

the protein of egg yolk is mainly oovitellin, which is a kind of phosphorus protein, a combination of phosphorus protein and lipid, or vitellin. Others include lipoproteins, glycoproteins, and denatured proteins. Vitellin exists in combination with 25% lecithin. This protein is called leeithinbitellin

the lipids in egg yolk are mainly phospholipids, and other complex lipids formed by glycolipids. The yolk pigment is golden and will fade gradually in the air. Eggs contain about 4% yolk oil (liquid emulsion at room temperature, mostly unsaturated fatty acids) and about 1% cholesterol

according to the phospholipid quality of egg yolk, P is the most abundant inorganic component in egg yolk, and there are also many Ca, Fe and Cu#

vitamins contain a, D, e, BL and B2. The yolk pigment is related to the components of vitamins. If the pigment is deeper, the amount of vitamins is also abundant. Its components are lutein, zeaxanthin, crptoxanth, etc（ β- Carotein) is related to the feed of chicken. If it is fed with germ, yellow Yushu, leguminous plants and grass, the color is dark

(4) enzymes

fresh eggs contain proteolytic enzymes, amylase, lipase, oxidase, digestive enzymes catalase and salicylase. There are lecithinase, phosphorase, esterase and peroxidase in the egg yolk. These enzymes will affect the changes of composition during the storage period of eggs, and are also related to the hatching of eggs