Shell • White or brown • Depends on ear flap color • Made of Calcium carbonate • Color does not affect flavor
Shell Membranes • 2 membranes inside each shell • Air cell forms between these membranes • 2nd line of defense against bacteria
Germinal Disc • Appears as a slight depression on the surface of the egg
White (Albumen) • Thin albumen-nearest to the shell • Mostly water, protein & minerals • Thick albumen stands up when egg is broken
Chalaza • Pair of spiral bands that anchor the yolk in the center of the thick albumen • More prominent-the freshest egg • Disappears when egg is cooked
Yolk Membrane • Clear seal holds the egg yolk • The fresher the egg the stronger the membrane
Yolk • Major source of egg’s vitamins, minerals, fat and ½ of the protein • Yolk color ranges from light yellow to deep orange, depending on hen’s food
Air Cell • Caused by contraction of the membranes after the egg is laid • Increases in size as egg ages • The fresher the egg, the smaller the air cell
Most common farm size is 10,000-20,000 hens although the largest farms may have 500,000 hens • By keeping different flocks at different stages there is a year round supply
Egg Grading • Temperature controlled storage • Best temperature & humidity to maintain freshness • Maximum 45 degrees F • Best at 40 degrees • Humidity approximately 70%
Most eggs are sterile when formed, but may become contaminated as they exit the hen's body or from any surface they contact. • Cleansing procedures protect the consumer from the bacteria. • Eggs are washed with water that is between 90°F and 120°F • Rinsed with hot water and chlorine • The eggs are then placed in cold storage and shipped.
Washing & sanitizing • High speed • Automatic – no hands • Thin coat of mineral oil applied to maintain freshness
Egg Candling • Quality Control • Shell condition • X-large air pockets • Blood spots • Yolk well centered
Weighing & Grading • Cartons are stamped with a “Best Before” date • Usually 30 days from grading • After that they are still safe but quality drops after 10 weeks
Grade AA • Firm white • Small air cell
Grade A • Used for commercial baking or further processing • Shell uncracked but rough textured
Grade B • Commercial processing only
Storage • Refrigerate at 45°F or below (do not freeze). • Store shell eggs in their box.
Eggs should be stored with the rounded end pointed up in order to keep the air cell on top and to help keep the yolk centered in the egg. • Never store eggs next to strong smelling foods because eggshells are porous and will allow strong odors to be absorbed into the egg over time.
Handling • Use only clean, uncracked eggs. • Wash eggs before cracking or hard boiling.
Preparation • Use Grade AA or A eggs for scrambling • Hold cold egg dishes below 40°F. • Hold hot egg dishes above 140°F.