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EGGS Prepared by: Daisy T. Bangayan UNIVERSITY OF SAINT LOUIS- TUGUEGARAO
OBJECTIVES Define the meaning of egg. Discuss the history, uses, and cooking issues of eggs Students will learn to identify the parts and structure of the egg. Identify the composition of the eggs. Enumerate the egg size and egg grading. Value the importance of eggs.
What Is an Egg? Eggs are poultry products from chicken, duck, and quail that eaten as food. An egg is a reproductive cell from which a new organism develops. This will occur only if the egg has been united with a male sperm cell (fertilized).
History Bird eggs have been valuable foodstuffs since prehistory, in both hunting societies and more recent cultures where birds were domesticated.
The chicken was probably domesticated for its eggs from jungle fowl native to tropical and subtropical Southeast Asia and India before 7500 BCE. Chickens were brought to Sumer and Egypt by 1500 BCE, and arrived in Greece around 800 BCE, where the quail had been the primary source of eggs.
In Thebes, Egypt, the tomb of Haremhab, built about 1420 BCE, shows a depiction of a man carrying bowls of ostrich eggs and other large eggs, presumably those of the Pelican, as offerings.
In ancient Rome, eggs were preserved using a number of methods, and meals often started with an egg course. The Romans crushed the shells in their plates to prevent evil spirits from hiding there.
In the Middle Ages, eggs were forbidden during Lent because of their richness. The word mayonnaise possibly was derived from moyeu, the medieval French word for the yolk, meaning center or hub. Egg scrambled with acidic fruit juices were popular in France in the 17th century; this may have been the origin of lemon curd.
The dried egg industry developed in the 19th century, before the rise of the frozen egg industry. In 1878, a company in St. Louis, Missouri started to transform egg yolk and white into a light-brown, meal-like substance by using a drying process. The production of dried eggs significantly expanded during World War II, for use by the United States Armed Forces and its allies.
In 1911, the egg carton was invented by Joseph Coyle in Smithers, British Columbia, to solve a dispute about broken eggs between a farmer in Bulkley Valley and the owner of the Aldermere Hotel. Early egg cartons were made of paper.
Parts and Structure of an Egg
Parts and Structure of an Egg 1. Yolk - This is the yellow or orange portion found in the center of the egg. - the yolk is encased in a colorless membrane called the vitelline membrane 2. White - this also called the albumen - the yolk is suspended in it by two yolk cords or chalazae ( Kah-lay-za)
Parts of an Egg 3. Shell membrane - there are two membranes, the inner and outer which are readily seen when peeling hard cooked eggs. 4. Shell - this is made up mainly of calcium carbonate.
Parts of an Egg When the egg is freshly laid, the shell is completely filled. The air cell is formed by contraction of the contents during cooling and by the loss of moisture. A high-quality egg has only a small air cell. The yolk is well-centered in the albumen and is surrounded by the vitelline membrane, which is colorless. The germinal disc, where fertilization takes place, is attached to the yolk.
Parts of an Egg On opposite sides of the yolk are two, twisted, whitish cord-like objects known as chalazae. Their function is to support the yolk in the center of the albumen. Chalazae may vary in size and density, but do not affect either cooking performance or nutritional value. A large portion of the albumen is thick. Surrounding the albumen are two shell membranes and the shell itself. The shell contains several thousand pores that permit the egg to "breathe."
Size of an Eggs Jumbo - 30 ounces per dozen Extra Large - 27 ounces per dozen Large - 24 ounces per dozen Medium - 21 ounces per dozen Small - 18 ounces per dozen Pee Wee - 15 ounces per dozen
Egg Grading 1.AA – shell -have whites that are thick and firm; yolks that are high, round, and practically free from defects; and clean, unbroken shells. Grade AA and Grade A eggs are best for frying and poaching, where appearance is important.
2. A-shell- eggs have characteristics of Grade AA eggs except the whites are "reasonably" firm. This is the quality most often sold in stores.
3. B-shell- clean to slightly stained, air cell over 3/16" deep, white-weaker and watery. eggs have whites that may be thinner and yolks that may be wider and flatter than eggs of higher grades. The shells must be unbroken, but may show slight stains. This quality is seldom found in retail stores because they are usually used to make liquid, frozen, and dried egg products, as well as other egg-containing products.
Cooking Issues Egg white coagulates, or solidifies, when it reaches temperatures between 144 °F and 149 °F (62.2 °C-65 °C). Egg yolk coagulates at slightly higher temperatures, between 149 °F and 158 °F (65 °C-70 °C).
If a boiled egg is overcooked, a greenish ring sometimes appears around egg yolk due to the iron and sulfur compounds in the egg. It can also occur when there is an abundance of iron in the cooking water.
The green ring does not affect the egg's taste; overcooking, however, harms the quality of the protein Chilling the egg for a few minutes in cold water until it is completely cooled prevents the greenish "ring” from forming on the surface of the yolk.
Cooking also increases the risk of atherosclerosis due to increased oxidization of the cholesterol contained in the egg yolk.
Uses It is sometimes separated from the egg whites and used in cooking (for mayonnaise, custard, hollandaise sauce, and creme brulee).
It is used in painting as a component of traditional egg-tempera. It is used in the production of egg-yolk agar plate medium, useful in testing for the presence of Clostridium perfringens.
Egg yolks also contains an antibody called antiglobulin. The antibody transfers from the laying hen to the egg yolk by passive immunity to protect both embryo and hatchling from microorganism invasion. Egg yolk can be used to make liqueurs such as Advocaat or eggnog. Egg yolks are used to extract Egg Oil which has various cosmetic, nutritional and medicinal uses.
Egg Cookery Egg cooked in the shell Hard-cooked Egg - Eggs must not be boiled but simmer for about 20 minutes for a hard- cooked egg.
The cooked egg should be immersed in cold water and flushed in running water immediately after cooking to avoid darkening of the yolk. The greenish coloration of the yolk is due to the formation of iron sulfide during cooking. Iron comes from the yolk and the sulfide from the white.
Characteristics -Tender albumen not rubbery -Yolk is well centered -No yolk darkening -Easy to peel
Rules to follow in the hard cooking of eggs -Use fresh eggs -Allow to stand overnight at room temperature -Simmer for 20 minutes -Put the egg in when water is about to boil to have less cracks. -Cool immediately in running water.
Soft – cooked egg – has a tender but firm albumen, yolk is slightly thickened yet not firm at the edges. A good soft cooked egg may be obtained by simmering for 5 minutes with enough water to cover the egg.
Eggs cooked out of the shell
Poached eggs are those broken out of the shell and dropped into simmering water to coagulate. A drop of vinegar gives a smooth textured product.
Fried eggs are the most popular breakfast preparation and sometimes called eggs coked sunny side up. The eggs are broken out of the shell and pan fried in small amount of oil without breaking the yolk. The upper surface of the yolk is basted with hot oil. Non- stick pan is recommended to use.
Shirred eggs – resembles fried eggs, except that it starts on top of the stove and finished in the oven individually.
Scrambled eggs- are prepared by whipping the whole egg out of the shell and pan frying just like fried egg. Another way is to whip the white first into stiff foam and add the yolk as whipping is continued. Milk may be added to lower the coagulation temperature and to affect a softer product.
Omelets are sophisticated scrambled eggs. The first part of the technique is similar for making scrambled eggs. The similarity ends there and the omelet emerges from the pan not as shapeless pile of curds on an attractive oval with light delicate texture. Many variations can be done in the preparations of omelets.
Souffles – a standard entree souffle consists of three elements: -Base – usually heavy bechamel -Flavor ingredients – cheese, vegetables, sea foods, meat -Egg whites – delicately beaten The ingredients are folded gently and bake in a souffle dish and served immediately from the oven to the dining table.
Unscramble the Scrambled Eggs 1. dirresh 3. lehls 4.geg 5. oymrbe 6. gingrad 7. iecckhn 9.orcuibtna 10. ingsw 11. Tapemertrue 12.llec 13.zalachae 2.olky 14. branemsem 15.izdeltirfe SEAT WORK 8. lesfofus
THANK YOU AND HAVE A NICE DAY!