The Effect of pH and Heat on the Ultrastructure of Thick and Thin Hen’s Egg Albumen

Electron microscopy techniques were used to investigate the differences between thick and thin egg albumen at pH 7.4 and pH 9.0. There was no difference between the thick and thin raw albumens at either pH. The cooked thick and thin albumens at pH 7.4 were similar and were characterized by numerous large spherical osmiophilic structures. The cooked thick and thin albumens at pH 9.0 consisted of condensed particles which were embedded in a filamentous matrix. The thick albumen at pH 9.0 had smaller and more numerous asymetric particles than the thin albumen. The observed differences are attributed to changes in the heat lability of the various proteins and in the protein-protein complexes.