A domestic fowl was given a standard feed supplemented witha 1% mineral mixture, and the eggs (test eggs) which the fowl laid were compared with those (standard eggs) obtained from a fowl given only the standard feed. We compared the difference in quality of the albumen and yolk during storage, the viscosity and hardness of the raw yolk, the strength of the vitelline membrane, heated albumen and yolk of the boiled egg, the hardness and coagulation of the thickly folded fried egg, and the tissue structure of the albumen and yolk of the boiled egg.. In addition, thickly folded fried and boiled test eggs were prepared for a sensory test with respect to the softness, hardness and taste by a panel of 25 people.
There was no difference in the quality of the albumen and yolk during storage between the test and standard eggs. However, the raw yolk showed higher values for viscosity, hardness and breaking stress of the vitelline membrane in the test egg than in the standard egg. The layers of the fibrous structure and granules in the thick albumen of the test eggwere more distinct than those of the standard egg, and the size of the yolk sphere in the test egg was more consistent than that of the standard egg. Furthermore, the granules were equally distributed in the heated yolk sphere of the test egg, while an uneven distribution of granules was observed in the standard egg. These results indicate a difference in the heat-induced structure between the testand standard eggs. This different structure hardened both the thickly folded fried egg and the albumen and yolk in the boiled egg. The test egg was significantly favored in the sensory test for making both thickly folded fried egg and boiled egg (p<0.001).