Chicken eggs are used in the diet.

Egg components and food composition

The components are:
a) shell (external casing with a medium-resistant structure)
b) albumen (commonly called “egg white”; approximately 60% of the egg's weight)
c) yolk (central part, from yellow to red, more nutritious; approximately 40% of the egg's weight)
d) air chamber (the space not occupied by the egg white and yolk).

The nutritional composition of the whole egg, and its parts, is as follows:

(except the shell, which is not edible)
Nutritional composition of the egg Components	Albumen	Yolk	Egg
WATERFALL	85-87%	49-51%	76.7%
PROTEINS	About 12%	16-18%	12.3%
FATS	0.2%	32-40%	9.2%
OTHER	1.6%	1%	1.8%

Eggs are the best food for the quality of their proteins, but they are not a complete food, because they lack carbohydrates, calcium and vitamin C (all other vitamins are present, however).
100 g of egg, from two eggs without the shell, provides 132 Kcal.

The egg white contains several proteins, the most abundant of which is ovalbumin; the yolk (red) contains phosphoric proteins, lipoproteins, and lecithin.
The 31.9% fat in the yolk is made up of approximately half saturated fatty acids, and the remaining half unsaturated fatty acids, mainly oleic acid and small amounts of linoleic, linolenic, and arachidonic acids.

Although egg yolks are rich in cholesterol (250 mg/yolk), it's important to remember that only 10% of total cholesterol comes from diet (the rest, a full 90%, is synthesized by our bodies); therefore, moderate egg consumption cannot significantly affect blood cholesterol levels.

Eggs may be contraindicated only in gallstones, because they can cause contractions of the gallbladder, resulting in colic spasms.

A fresh egg, just laid by a hen, has no air chamber. This is formed due to the porosity of the shell, which allows air to gradually penetrate inside (obviously, the size of the air chamber increases as the days go by, but only up to a certain point, that is, until the external air pressure is counterbalanced by that of the chamber inside the egg).
Above all, freshness, and also weight, are the two important qualities of eggs.

Quality categories for freshness.

Regarding freshness (primary quality factor), we have 2 categories, “A” and “B”.
Category “A” eggs are intended for direct consumption, meaning they are authorised for sale to consumers if all the requirements set forth in the current regulations for this category are met.
According to the European Regulation, the direct sale of category B eggs to consumers is prohibited. They can only be sold to food processing industries (e.g., confectionery, fresh pasta, etc.) or to non-food industries.

Below we report the relevant requirements for each category:

• CATEGORY “A”, eggs intended for direct human consumption
• CATEGORY “A Extra”

“very fresh” eggs, untreated and unrefrigerated, with an air chamber no greater than 4 mm, and usable up to the 7th day after packaging or the 9th day after being laid; after this period the eggs can be marketed with reference only to category A (having lost the “extra” qualification);

• CATEGORY “A”

fresh, untreated and unrefrigerated eggs, with an air space of not more than 6 mm; “recommended sell-by date”, or final date for the sale of eggs to the consumer (optional), calculated as 21 days from the laying date and obtained by subtracting 7 days from the minimum durability date (28 days), considered as an additional period for consumption by the consumer;

• CATEGORY “B”, eggs not intended for direct human consumption
• Second-quality or downgraded eggs

Category B eggs include eggs that do not meet the requirements for Category A eggs. They may only be sold to food industry businesses recognized pursuant to Article 6 of Directive 89/437/EEC or to the non-food industry.
These are two- to three-week-old eggs (air space between 6 and 9 mm), untreated and unrefrigerated. They are second-quality or downgraded eggs, intended for processing into egg products or the non-food industry.
Their packaging bears a stamp clearly indicating their destination.

Quality categories for weight.

Classification by WEIGHT category:

1. XL very large, over 73 g;
2. Large, 63 g to 73 g;
3. M medium, from 53 g to 63 g;
4. Small, less than 53g.

Labelling and various regulations.

The following information must appear on the packaging:
A. The name of the packing center;
B. The number of eggs;
C. The quality category relating to “freshness”;
C. The quality category relating to weight;
D. The date of egg laying and the last date for releasing the eggs for consumption (usually 9 days);
E. The expiry date, i.e. the wording: “Best before …” (generally, two weeks after the last date for releasing the eggs for consumption);
F. Laying hens rearing system, and traceability code.

Recently, the Alemanno law, in force since 04/04/2004, introduced an 11-letter alphanumeric code, which uses the first letter to indicate the breeding system and the remaining 10 for traceability.
The code has a generic format like this, x yy zzz ww jjj , where:
x identifies the system of breeding laying hens.
yy zzz ww respectively identify the State of production, ISTAT code of the Municipality and the acronym of the Province where the producer is located.
jjj is the identification code of the individual production farm.
The breeding systems are codified as follows:

0 = organic
1 = outdoors
2 = on the ground
3 = in cage

Example: 1 IT 084 SA 123, where:
1: Identify the method of raising laying hens (outdoors);
IT: Italy, or in the example, the country of production;
084: ISTAT code of the municipality where the producer is located (Cava de' Tirreni);
SA: abbreviation of the province where the producer is located;
123: identification code of the individual production farm.

If eggs are sold loose, a tag must be placed on the basket, which must contain the same information as above, which is valid for the packaging.

Eggs imported from abroad must have the name of the country of origin stamped on the shell.

Fresh eggs (Category A) remain fresh for 3-4 days if stored outside the refrigerator; they remain fresh much longer if, immediately after purchase, they are refrigerated at a temperature between -1°C and +1°C; at temperatures below -3°C, eggs freeze.
Of course, "freshness" depends primarily on the storage method, but also on the collection system; the best collection system is hygienic, followed immediately by transferring the eggs to the refrigerator.

SEE YOU NEXT LESSON AND GOOD LUCK TO EVERYONE IN THE KITCHEN.