LPT 321: Meat Science (1+1)

INTERNAL QUALITY OF EGGS

• Candling is done to observe the internal qualities of eggs though a source of light such as depth of air cell, free or movable air cell, bubbly air cell, blood spots and meat spots in the egg, etc.
• Depth of air cell
  • The depth of the air cell is the distance from its top to its bottom when the egg is held air cell upward.
• Free air cell
  • An air cell that moves freely towards the upper most point in the egg as the egg is rotated slowly.
• Bubbly air cell
  • A ruptured air cell resulting in one or smaller separator air bubbles usually floating beneath the main air cell.

Grading of chicken eggs

• Eggs are graded and marketed based on
  • weight and
  • quality

BIS standards based on weight

• Extra large - 60 g and above
• Large - 53 to 59 g
• Medium - 45 to 52 g
• Small - 38 – 44 g

BIS standards based on quality

As per BIS standards there are 2 quality grades namely A and B

Grade		Weight/egg (gm	Shell	Air cell	White	yolk
Quality grade	Weight grade
A	Extra large	60&above	Clear, unbroken and sound. Shape is normal	Up to 4 mm in depth. Practically normal	Clear reasonably firm	Fairly well centred. Practically free from defects, outline indistinct
A	Large	53 to 59
A	Medium	45 to 52
A	Small	38 to 44
B	Extra large	60&above	Clear to moderately stained and sound, shape is slightly abnormal	8 mm in depth, may be free and slightly bubbly	Clear, may be slightly weak	May be slightly off centered. Outline slightly visible
B	Large	53 to 59
B	Medium	45 to 52
B	Small	38 to 44