Telur Ayam

April 25, 2008 pukul 4:39 am | Ditulis dalam Ragam | 15 Komentar

Mengenal Bagian-bagian telur Ayam yookk…!!

Schematic of a chicken egg:

1. Eggshell

Bumpy and grainy in texture. The outer eggshell is made almost entirely of calcium carbonate (CaCO3) and is covered with as many as 17,000 tiny pores. It is a semipermeable membrane, which allows air and moisture to pass through its pores. The shell also has a thin outermost coating called the bloom or cuticle that helps keep out bacteria and dust (see below 15).

2. Outer shell membrane
3. Inner shell membrane

These two membranes — outer and inner — are just inside the shell surrounding the albumen (white). The two membranes provide an efficient defense against bacterial invasion and are made partly of keratin. The outer membrane sticks to the egg shell while the inner membrane sticks to the albumen. When an egg is first laid, it is warm. As it cools, the contents contract and the inner shell membrane separates from the outer shell membrane to form the air cell (see 14 below).

4. Chalaza — are twisted in opposite directions and serve to keep the yolk centered. Opaque ropes of egg white. The more prominent the chalazae, the fresher the egg.

5. Exterior albumen (outer thin albumen) — The outer thin albumen is a narrow fluid layer next to the shell membrane.

6. Middle albumen (inner thick albumen) —The inner thick white (chalaziferous layer) is a dense, matted, fibrous capsule of albumen around the vitelline membrane of the yolk. The matted fibrous capsule terminates on each end in the chalazae, which are twisted in opposite directions and serve to keep the yolk centered. This part of the egg is a excellent source of riboflavin and protein. In high-quality eggs, the inner thick albumen stands higher and spreads less than thin white. In low-quality eggs, it appears thin white.

7. Vitelline membrane — The clear casing that encloses the egg yolk. When an egg is said to be “mottled”, the yolk surface is covered with many pale spots or blotches. The strength and integrity of the vitelline membrane are very important in preventing egg yolk mottling.

8. Nucleus of pander — a plug of whitish yolk, with no particular significance for development and whose function is purely a nutritive one, like the rest of the yolk. (See: Int. Schmitt S., (2005) J. Dev. Biol. 49: 1-8).

9. Germinal disk (blastoderm) — a small, circular, white spot (2-3 mm across) on the surface of the yolk; it is where the sperm enters the egg. The nucleus of the egg is in the blastodisc. The embryo develops from this disk, and gradually sends blood vessels into the yolk to use it for nutrition as the embryo develops.

10. Yellow yolk — a major source of vitamins, minerals, almost half of the protein, and all of the fat and cholesterol. The yolk contains less water and more protein than the white, some fat, and most of the vitamins and minerals of the egg. These include iron, vitamin A, vitamin D, phosphorus, calcium, thiamine, and riboflavin. The yolk is also a source of lecithin, an effective emulsifier. Yolk color ranges from just a hint of yellow to a magnificent deep orange, according to the feed and breed of the hen.

11. White yolk — Also known as, the latebra is an area of white yolk located in the center of the yolk. It is lower in fat and therefore stands out as a bright white area in many Magnetic Resonance Images. The specific function of the latebra is uncertain but it may act as a central structure around which the additional layers of the yolk are formed.

12. Internal albumen (Chalaziferous albumen)— The inner thick white (chalaziferous layer) is a dense, matted, fibrous capsule of albumen around the vitelline membrane of the yolk. The matted fibrous capsule terminates on each end in the chalazae, which are twisted in opposite directions and serve to keep the yolk centered.

13. Chalaza chalazae, which are twisted in opposite directions and serve to keep the yolk centered. The more prominent the chalazae, the fresher the egg. chalazae, which are twisted in opposite directions and serve to keep the yolk centered.

14. Air cell — An air space forms when the contents of the egg cool and contract after the egg is laid. The air cell usually rests between the outer and inner membranes at the egg’s larger end. As the egg ages, moisture and carbon dioxide leave through the pores of the shell, air enters to replace them and the air cell becomes larger.

15. Cuticle or bloom — The shell is produced by the shell gland (uterus) of the oviduct, and has an outer coating, the bloom or cuticle. The cuticle somewhat seals the pores and is useful in reducing moisture losses and in preventing bacterial penetration of the egg shell. Most of cuticle is removed from table eggs when they are mechanically washed.

More than half the calories found in eggs come from the fat in the yolk; a 100 gram chicken egg contains approximately 10 grams of fat. People on a low-cholesterol diet may need to reduce egg consumption, although most of the fat in egg is unsaturated fat and may not be harmful. The egg white consists primarily of water (87%) and protein (13%) and contains no cholesterol and little, if any, fat.

A health issue associated with eggs is contamination by pathogenic bacteria like Salmonella enteritidis. Contamination of eggs exiting a female bird via the cloaca may also occur with other members of the Salmonella group, so care must be taken to avoid the egg shell becoming contaminated with fecal matter. In commercial practice, eggs are quickly washed with a sanitizing solution within minutes of being laid. The risk of infection from raw or undercooked eggs is dependent in part upon the sanitary conditions under which the hens are kept.

Health experts advise people to refrigerate eggs, use them within two weeks, cook them thoroughly, and never consume raw eggs . As with meat, containers and surfaces that have been used to process raw eggs should not come in contact with ready-to-eat food.

One of the most common food allergies in infants is eggs. Infants usually have the opportunity to grow out of this allergy during childhood, if exposure is minimized. Generally, physicians will recommend feeding only the yolks to infants because of the higher risk of allergic reaction to the egg white.

Manfaat Telur Ayam dari Segi Kesehatan:

In spite of the high cholesterol content of eggs, there are several health benefits relating to the inclusion of eggs in the diet—in limited quantities, of course. Consider the following points: Eggs are one of the best sources of protein, vitamins, and minerals. The quality of the protein found in eggs is of a higher quality than the protein found in meat and fish. Eggs are low in calories. One large egg has only about 75 calories. The high protein egg white averages only about 17 calories and has no fat or cholesterol, which makes it an excellent diet food. There are nutrients in eggs that are beneficial in preventing macular degeneration, which is the leading cause of blindness in the elderly. Eggs are rich in choline, which is helpful in fetal brain development. Choline levels in women drop during pregnancy, so it may be beneficial for women to consume eggs during pregnancy.

Eggs and Cholesterol

The average large chicken egg has about 213 milligrams of cholesterol, which is all contained within the yolk. Medical studies have shown that excess cholesterol in the diet can raise the level of cholesterol in the blood, causing major health problems such as heart disease. Since the body produces all of the cholesterol it needs for normal functions, eating large quantities of cholesterol rich foods may be unhealthy. It is recommended that the intake of cholesterol in one day should not exceed 300 milligrams. With one egg yolk containing 213 milligrams, it is clear that the recommended daily maximum can be quite easy to exceed.

There are a number of ways in which the dietary guidelines for cholesterol can be followed, yet permit eggs to remain a part of the diet. Consider the following points: When multiple eggs are desired for an omelet or scrambled eggs, use two egg whites for every one yolk. This will decrease the amount of cholesterol per serving. Eliminate all of the egg yolks from egg dishes, such as omelets, scrambled eggs, or egg bakes. Since egg whites contain no cholesterol, none of the cholesterol in the resulting dish will be from the eggs. Use egg substitutes for omelets and scrambled egg dishes. A number of products are available that incorporate egg whites with non-egg ingredients that mimic the look and taste of the egg yolks. Staying within the dietary guideline of 300 milligrams of cholesterol a day may be difficult to do for many of us; however, it might be easier to stay within the recommended weekly total of no more than 2100 milligrams. If you exceed the daily total on one or two days of the week, you can cut down or eliminate cholesterol on other days of the week in order to remain under the recommended weekly level. Even if you average one egg per day, you can still eat very well and remain under the 300 milligram recommended daily maximum of cholesterol. This can be achieved simply by eating more fruits, vegetables, and grains and cutting back on fatty meats, butter, oils, and junk foods.

Kandungan Nutrisi Telur Ayam:

Chicken Eggs Based on One Large Egg (50 g)
Component	Whole Egg		Egg White		Egg Yolk
	Quantity	% DV	Quantity	% DV	Quantity	% DV
Calories	75	4%	17	1%	58	3%
Total Fat	5.0 g	8%	0.0 g	0%	5.0 g	8%
Saturated	1.6 g	8%	0.0 g	0%	1.6 g	8%
Monounsaturated	2.0 g		0.0 g		2.0 g
Polyunsaturated	0.7 g		0.0 g		0.7 g
Cholesterol	213 mg	70%	0.0 g	0%	213 mg	70%
Carbohydrate	0.65 g	<1 %	0.34 g	<1 %	0.31	0 %
Protein	6.7 g	13%	4.0 g	7%	2.7	5%
Vitamins
Vitamin A	244 IU	5%	0.0 IU	0 %	244 IU	5%
Vitamin C	0.0 mg	0%	0.0 mg	0%	0.0 mg	0%
Vitamin D	18.3 IU	4%	0.0 mg	0%	18.3 IU	4%
Vitamin E	0.5 mg	2%	0.0 mg	0%	0.5 mg	2%
Choline	216 mg		0.45 mg		215.5 mg
Thiamin	0.031 mg	2%	0.002 mg	<1%	0.029 mg	2%
Riboflavin	0.254 mg	14%	0.151 mg	9%	0.106 mg	5%
Niacin	0.037 mg	<1%	0.035 mg	<1%	0.002 mg	<1%
Vitamin B6	0.1 mg	3%	0.0 mg	0%	0.1 mg	3%
Folate	23.5 mcg	6%	1.0 mcg	<1%	22.5 mcg	6%
Vitamin B12	0.6 mcg	11%	0.07 mcg	<1%	0.53 mcg	10%
Pantothenic Acid	0.627 mg	7%	0.040 mg	<1%	0.587 mg	7%
Vitamin K	0.1 mcg		0.0 mcg		0.1 mcg
Minerals
Calcium	26.5 mg	3%	2.0 mg	<1%	23.5 mg	3%
Iron	0.6 mg	3%	0.01 mg	<1%	0.59 mg	3%
Magnesium	5.0 mg	2%	4.0 mg	2%	1.0 mg	<1%
Phosphorus	89.0 mg	9%	4.0 mg	<1%	85.0 mg	9%
Potassium	67.0 mg	2%	54.0 mg	2%	13.0 mg	<1%
Sodium	63.0 mg	3%	55.0 mg	2%	8.0 mg	<1%
Zinc	0.6 mg	4%	0.0 mg	0%	0.6 mg	4%
Copper	0.007 mg	3 %	0.002 mg	<1%	0.005 mg	2%
Manganese	0.012 mg		0.001 mg		0.011 mg
Selenium	15.8 mcg		7.0 mcg		8.8 mcg

Tipe-tipe Telur Ayam:

Standard Chicken Eggs White Eggshells Chicken Breed: Leghorn, Ancona, and others Commercially produced chicken eggs are used more often than any other type of chicken egg and are the eggs most commonly found in food stores. Chicken eggs with white shells make up the bulk of the eggs sold in food stores. Occasionally, nonwhite eggshell colors are available, especially from local producers and in farmers markets. The color of the shell is determined by the breed of the hen and has nothing to do with the flavor, texture, or nutritional value of the egg. The only factors that may have an affect on any of these characteristics are the age of the egg and the diet of the hen. Brown eggshells are the most common color available, but green, blue, pink, and light red colors are sometimes seen.

Other Chicken Eggshell Colors Brown Eggshells Chicken Breed: Rhode Island Red and others Light Blue Eggshells Chicken Breed: Americana Light Green Eggshells Chicken Breed: Americana Light Pink Eggshells Chicken Breed: Americana Dark Brown, Rust, or Red Eggshells Chicken Breed: Sexlink, Maran, Wesummer, and others Light Rust or Light Red Eggshells Chicken Breed: Wyandotte and others

Fertile Eggs The term fertile egg refers simply to an egg that can be incubated and developed into a chick. Many people mistakenly believe that fertile eggs are more nutritious than non-fertile eggs, but there is no difference in the nutrient value between the two. Fertile eggs have higher production costs; therefore, they are more expensive for the consumer. Fertile eggs also spoil faster than non-fertile eggs.

Organic Eggs Organic eggs are produced from hens that have been given feed in which all of the ingredients were grown without the aid of commercial fertilizers, pesticides, or herbicides. This results in higher production costs, which in turn, makes organic eggs more expensive for the consumer than non-organic. In terms of nutritional value, organic eggs are no different than non-organic eggs.

Free-range Eggs Free-range is the name given to eggs produced by hens that have been raised outdoors (rather than inside large buildings with a controlled environment); however, because of climate considerations in many locales, most hens are not raised entirely in the open. Eggs may be called free-range if the hens have daily access to the outdoors but may not actually spend that much time outdoors. The cost of a free-range egg is higher because of additional costs encountered by free-range egg producers, but there is essentially no difference between a free-range egg and an egg produced from a confined hen. There is no difference in the flavor or texture, and the nutritional value is also the same.

scienceofcooking.com

en.wikipedia.org;  recipetips.com

Egg Tips Scrambled Eggs Scrambled eggs may turn slightly green when cooked at too high a temperature or when the eggs are allowed to sit in the pan for long periods. To help prevent “green scrambled eggs,” don’t overcook the eggs, and always serve the eggs when still moist. Do not hold the eggs in the pan for long periods. If the eggs must be held for a while before serving, don’t leave the pan directly on the burner of the stove; rather, place the pan inside another pan containing warm water to keep the eggs heated. Hard-Cooked Eggs If your hard-cooked eggs happen to become mixed up with uncooked eggs, it is easy to figure out which is which. When you spin an egg on its side on a flat surface and it does not wobble, it is an indication that the egg is hard-cooked. Poached Eggs Adding a bit of vinegar to the poaching water will help set the eggs more quickly, creating a pleasing shape. This also helps to prevent streamers of egg white from moving outward from the egg while it is being cooked. Egg Substitutions Substituting Egg Whites for Whole Eggs It may not be possible to substitute egg whites for whole eggs in some baked recipes because the results will be substandard; but it is possible to use only egg whites in a number of other egg dishes, such as scrambled eggs or omelets, which will eliminate the cholesterol. Omelets When making omelets or scrambled eggs, use two egg whites and two whole eggs to create the same volume as three whole eggs. This allows you to enjoy egg yolks while cutting back on the cholesterol level. Raw or Partially Cooked Eggs Traditional recipes that call for raw or partially cooked eggs may benefit from the use of egg substitutes, such as egg white substitutes, meringue powder, or pasteurized whole eggs. The risk of bacterial contamination is greatly reduced with the use of these products.