Yellow Colour of Egg Yolk

Correct Answer: Carotene

The yellow-orange colour of egg yolk is primarily due to carotenoid pigments, particularly carotene (β-carotene) and xanthophylls deposited from the hen's diet.

Important Note

• Carotene: Responsible for yellow-orange yolk colour — derived from feed (maize, green leaves).
• Xanthophyll: Also a carotenoid; responsible for yellow colour in skin and shanks of poultry. In some references, xanthophylls also contribute to yolk colour.
• Riboflavin (Vitamin B2): Responsible for greenish colour in egg white (albumin) — not yolk.
• Biotin: A B-vitamin involved in fat metabolism, not pigmentation.

Feeding maize (corn) or dried marigold petals enriches yolk colour due to their high carotenoid content.