Egg

Eggs

The most popular and widely used eggs are of hens in India, although eggs of turkeys, guinea fowls, and ducks are also used. The colour of egg shells and egg yolks varies with the breed of hen and the food they eat; but this makes no difference to the food value. They are rich in proteins and contain valuable amounts of iron and vitamin A&B. The ideal storage temperature for eggs is 2-5 degree C.

Food value:

 Eggs have been described as a “complete food”. One egg is equal to seventy calories of energy and contains carbohydrates, fats, proteins, mineral salts, vitamins and water.

Vitamins A, B, D, are all necessary for health and growth; iron, phosphorus and calcium are essential for building and maintaining healthy bodies. The average of egg shell, yolk and egg white in an egg is : 10%, 30% and 60%. Water constituency in egg is about 73%.

Structure of an egg:

Shell:

It is the outer covering of the egg and is composed of calcium carbonate. It may be white or brown depending upon the breed of the chicken. The colour of the shell does not affect cooking quality, character or nutrition.

Yolk:  

This is the yellow portion of an egg. Colour of yolk varies with the feed of the hen, but does not indicate the nutritional content.

Vitelline:  

It is a clear seal that holds or surrounds the egg yolk.

Chalazae:                    

These are the twisted cordlike strands of the egg white. They anchor the yolk in the centre of the egg. Prominent chalazae indicate high quality.

Shell membranes:  

Two shell membranes, inner and outer membrane, surround the albumen. They form a protective barrier against bacteria.

Air cell:

It is the pocket of air formed at the large end of the egg. Air cell forms between the membranes. This is caused by the contraction of the content on cooling after egg is laid. The air cell increases with the age of the egg as there is considerable amount of moisture loss.

Thin albumen:

It is nearest to the shell. When the egg is broken there will be a clear demarcation of the thin and thick albumen. As the egg gets older these two albumens tend to mix into one another. This is again a test of good and fresh egg.

Thick albumen:

It stands high and spreads less than the thin white in a high quality egg. It is an excellent source of riboflavin and protein.

Classification:

Basis of classification

Source(bird)

Farm & feed

Grade

Sizes

US

weight

European

Weight

Hen

Battery farm

AA

Jumbo

73

Extra large

73

Duck

Barn laid

A

Extra large

63

Large

63

Types

Turkey

Free range

B

Large

53

Medium

53

Goose

Organic

C

Medium

45

Small

45

Pigeon

Vegetarian

Small

40

Quail

Omega-3

Peewee

35

Guinea fowl

Vitamin enhanced

Source of egg:

Eggs are named after the birds that laid the eggs. Eggs can be distinguished by size and colour of the shell. Various birds are like hen, turkey, duck etc.

Farm and feed:

Eggs are named after the farming method employed or the feed provided to the bird to enhance a particular nutrient in the egg.

Grade:

Eggs are named after the quality grades awarded to them based upon set quality factors/parameters.

Sizes:

Eggs are named after their sizes, which are assigned to them based upon their weights. The sizing is based upon per dozen of eggs, but is represented as weight of individual egg after taking out mean weight per egg for ease.

Selection of eggs:

Physical appearance:

When purchasing eggs one should observe the physical appearance of eggs; no cracks, no dirt, colour and size.

By looking/finding for a “bloom”, that gives it a feeling much like that of a thin lime coating.

Candling:

This method of determining the freshness of eggs consists of placing a piece of cardboard containing a hole, a little smaller than an egg between the eye and a light, which may be from candle or electric light and holding the egg in front of the light. The rays passing through the egg show the condition of the egg, the size of its air cell, the growth of mould, or spoiling of the egg by any ordinary means.

Shaking:

One can determine the freshness of an egg by shaking it. When the water inside the shell evaporates, the yolk and white shrink so much that they can be felt moving from side to side when the egg is shaken. Staler the egg, more pronounced the movement becomes.

Floating:

A test for freshness which consists in placing the eggs in glass containing water will be found effective. A perfectly fresh egg will sink when it is put into the water, but if the egg is three weeks old the broad end will rise slightly from the bottom of the glass. An egg that is three months old will sink into the water until only a slight portion of the shell remains exposed; whereas, if the egg is older or stale, it will rise in the water until nearly half of it is exposed.

Storage of eggs:

Ø  Eggs should be used within a month and stored unwashed, with the pointed end down, in the cold part of the refrigerator.

Ø  Washing the egg makes the shell permeable to smells, so strong smelling foods, such as cheese, onion, garlic and ginger, should not be stored near the eggs.

Ø  A hardboiled egg will keep for four days if unshelled and two days if shelled.

Ø  Once broken, egg yolk will keep for 24hrs. And egg white for 6to12 hrs, in a refrigerator.

Ø  Wider end of egg should be kept up, while storing.

Ø  Average temperature for storage is 2-5degree C.

Uses of eggs :

v  Binding: addition of eggs to minced meat and mashed vegetables etc. helps to bind the mixture. As heat coagulates, the proteins are bound into a cohesive mass.

v  Coating: the egg and egg batter help to give a coat to the food items and prevent them from disintegrating and give them a protective coating.

v  Leavening: by beating the egg whites, foam is made up of air bubbles, surrounded by a thin elastic film of egg white. This mixture, when added to products such as sponge cake, meringues, etc. increases the volume and the egg white film hardens.

v  Emulsifying: eggs form stable emulsions. eggs are used as an emulsifier in mayonnaise, ice creams, cakes etc.

v  Thickening: eggs help to improve the consistency of gravies, curries, sauces and soups. Egg liaison used in soups and sauces help to thicken and improve consistency.

v  Decoration and garnishing of dishes: slices, sieved, or quarters of boiled eggs are used to garnish dishes such as salad, biryanis, curries etc.

v  Clarifying: consommés are clarified with egg white.

v  Taste, flavour, shine: enhances colour and sheen, enrich and enhance the flavour and taste. Egg wash gives a shiny appearance.

Various courses in which eggs are used:

ü  Hors d’oeuvre: used for various hors d’oeuvres, such as egg mayonnaise, egg stuffed etc.

ü  Soups: in the preparation of consommés, thickening of veloutes, for garnishes such as slices of savoury custard (royal), threaded eggs (xaviere).

ü  Eggs: they are placed as the third course before the fish. They are featured only on luncheon menus and not dinner. The egg dishes served are scrambled, encocotte, egg portugaise etc.

ü  Farinaceous: for raviolis, cannellonies, and noodles, eggs are used to prepare the paste.

ü  Fish: batters are prepared out of eggs for the coating prior to crumbing.

ü  Meat and poultry: chicken cutlets, hamburgers, meat, beef get their binding fro egg.

ü  Salads: hard boiled eggs are used in salad as main ingredient, border or as a garnish.

ü  Sweets: eggs bind and enrich the pudding and sweet dishes.

ü  Savouries: scotch woodcock, welsh rarebit, cheese soufflé are all made with eggs.

Methods of cooking eggs:

      Boiling: eggs are boiled in water for different degrees like soft, medium and hard, which depends on the timing of cooking.

      Poaching: eggs are poached in simmering water with addition of vinegar or lemon juice. Egg ring can be used for a better shape.

      Scrambling: beaten egg and milk are mixed together and cooked in butter at low flame.

      Frying: eggs are fried in a pre heated pan at low flame. Can be sunny side up, turned over, over easy.

      Omelette: stir the mixture well then cook in pre heated pan.

      Baking: place egg in a ramekin dish, cover with cream to prevent drying.