Composition of the chicken egg
The physical composition on the avian egg can be seen in Table 1, below. The yolk accounts for 32-35%, the albumen 52-58% and the shell accounts for only 9-14% of the total egg components.
Table 1. Nutrient composition of the egg (%)
Egg components | ||
---|---|---|
Nutrient | Albumen | Yolk |
Protein | 9.7 – 10.6 | 15.7 – 16.6 |
Lipid | 0.03 | 31.8 – 35.5 |
Carbohydrate | 0.4 – 0.9 | 0.2 – 1.0 |
Water | 84.3 – 88.8 | 48 |
Element | ||
Sulphur | 0.195 | 0.016 |
Potassium | 0.145 – 0.167 | 0.112 – 0.360 |
Sodium | 0.161 – 0.169 | 0.070 – 0.093 |
Phosphorus | 0.018 | 0.543 – 0.980 |
Calcium | 0.008 – 0.02 | 0.121 – 0.262 |
Magnesium | 0.009 | 0.032 – 0.128 |
Iron | 0.0009 | 0.0053 – 0.011 |
Adapted from Li-Chan, ECY, Powrie, WD and Nakai, S (1995) The chemistry of eggs and egg products, In Egg Science and Technology, WJ Stadelman and OJ Cotterill (Eds), The Haworth Press Inc, New York.
Table 2. Lipid composition of the egg yolk
Lipid Composition | % |
---|---|
Triglycerides | 63 |
Phospholipids | 31 |
Cholesterol | 4 |
Other (including fat soluble vitamins) | 2 |
Fatty Acid Composition | % |
Saturated fatty acids | 35 – 45 |
Unsaturated fatty acids | 55 – 65 |
Monounsaturated fatty acids | 35 – 50 |
Linoleic acid | 10 – 20 |
Polyunsaturated fatty acids | 3 – 5 |
Adapted from Larbier, M and Leclercq, B (1994) Nutrition and feeding of poultry, Nottingham University Press, Nottingham.
Table 3. Protein composition of the egg albumen
Principal Protein Content | % |
---|---|
Ovalbumin | 55 |
Covalbumin | 13 |
Ovomucoids | 11 |
Ovoglobulin | 8.5 |
Lysozyme | 3.7 |
Ovomucins | 1.5 |
Flavoprotein | 0.8 |
Avidin | 0.05 |
Adapted from Larbier, M and Leclercq, B (1994) Nutrition and feeding of poultry, Nottingham University Press, Nottingham.
Table 4. Elemental composition of the eggshell
Element / Compound | % |
---|---|
Calcium carbonate | 98.2 |
Magnesium | 0.9 |
Phosphorus (phosphate) | 0.9 |
Adapted from Romanoff, AL and Romanoff, AJ (1949) The Avian Egg, John Wiley and Sons, New York.