An egg is composed of protein and egg yolks. The yolk contains proteins, but also fat (in the chicken egg, on average, 11.5% fat) and cholesterol. Fat contained in the yolk, mainly polyunsaturated and therefore harmless. Protein is composed of 90% of the water, 10% of the protein contains no cholesterol and contains virtually no fat.The composition of egg whiteIn a chicken egg white is composed of: water (86%), proteins (12.7%), fat (0.3%), carbohydrates (0.7%), glucose, various enzymes (proteinase,