EGG

• What types of animals lay eggs?

  Birds, amphibians, reptiles, and fish
• Why are chicken eggs considered popular for consumption?

  They are an inexpensive source of protein
• What is the reference standard for protein assessment?


  Chicken eggs are used as a reference standard
• What are the three main parts of an egg?

  • Shell
  • Egg white
  • Egg yolk
• What is the outer eggshell primarily made of?

  Calcium carbonate (CaCO3)
• What is the function of the pores in the eggshell?


  They allow air and moisture to pass through
• What is the bloom or cuticle on an eggshell?


  It is a thin outermost coating that helps keep out bacteria and dust
• What are the two membranes inside the eggshell called?


  Outer and inner shell membranes
• What is the role of the chalazae in an egg?


  They anchor the yolk in the center of the egg
• What does the exterior albumen refer to?


  It is the outer thin albumen next to the shell membrane
• What is the composition of the inner thick albumen?


  It is a dense, matted, fibrous capsule of albumen around the vitelline membrane
• What does the vitelline membrane do?


  It holds the egg yolk
• What does the yellow yolk contain?


  Less water and protein than the white, some fat, and most vitamins and minerals
• What is lecithin and where is it found in an egg?


  Lecithin is an effective emulsifier found in the yolk
• What forms the air cell in an egg?


  An air space forms when the contents of the egg cool and contract
• Where does the air cell rest in an egg?


  Between the outer and inner membranes at the egg's larger end
• What happens to the air cell as the egg ages?


  It becomes larger as moisture and carbon dioxide leave
• What is the germinal disk in an egg?


  A small, circular white spot where the sperm enters the egg
• What is the protein content of an egg by weight?


  About 12.6% of the edible portion
• How is protein distributed in an egg?


  • Egg white: 57%
  • Egg yolk: 43%
• What is the protein content of different types of eggs per 100g?


  • Whole raw fresh egg: 12.56g
  • Egg white raw fresh: 10.90g
  • Egg yolk raw fresh: 15.86g
  • Whole dried egg: 48.37g
  • Whole cooked hardboiled: 12.58g
  • Whole cooked fried: 13.61g
  • Whole cooked omelet: 10.57g
• What essential amino acid is rich in eggs?


  Leucine
• How does the amino acid composition of an egg relate to human needs?


  It matches the requirement of amino acids by the human body
• What percentage of water is in egg white?


  About 90%
• How many different proteins are approximately found in egg white?


  About 40 different proteins
• What are the main types of proteins present in egg white?

  • Ovalbumin: 54%
  • Ovotransferrin: 12%
  • Ovomucoid: 11%
  • Ovoglobulin G2: 4%
  • Ovoglobulin G3: 4%
  • Ovomucin: 3.5%
  • Ovoinhibitor: 1.5%
  • Lysozyme: 3.4%
  • Ovoglycoprotein: 1%
  • Flavoprotein: 0.8%
  • Ovomacroglobulin: 0.5%
  • Avidin: 0.05%
  • Cystatin: 0.05%
• What is ovalbumin?


  It is the most common protein in egg white
• What is the composition of ovotransferrin?


  It is composed of 686 amino acids and has antimicrobial properties
• What is unique about ovomucoid?


  It has a stable spatial structure that is not denatured even upon boiling
• What are the major proteins in egg yolk?

  • Lipovitellin
  • Livetin
  • Phosvitin
• What is phosvitin?


  It is a type of phosphoprotein that has iron and calcium binding capacity
• What is powdered egg white?


  • Dehydrated egg whites
  • Ground into a powder
  • Also sold as spray-dried egg whites
• What are the steps in the production of egg white powder?

  1. Breaking the eggs
  2. Separating egg white from yolk
  3. Filtering to remove contaminants
  4. Adjusting pH and storing
  5. Reverse osmosis treatment
  6. Fermentation to break down glucose and fat
  7. Cooling and spray drying
  8. Dry heating
• What is the purpose of adjusting the pH during egg white processing?


  To ensure optimal conditions for storage and processing
• What temperature is the egg white cooled to during processing?


  4 degrees Celsius
• What is the final step in the production of albumen powder?


  Dry heating in large conical dry blenders at 87 degrees Celsius for 12 hours
• What are the advantages of egg white powder?


  • Can be stored at room temperature
  • Good shelf life
  • Time-saving
  • Requires no refrigeration