Ultrastructural Changes in Unwhipped and Whipped Egg Albumen Containing Sodium Hexametaphosphate and Triethyl Citrate Plus Trisodium Citrate

The electron microscope was employed to determine ultrastructural changes in egg albumen without and with sodium hexametaphosphate and triethyl citrate plus trisodium citrate. Unwhipped and whipped albumens containing sodium hexametaphosphate were relatively free of major zones of compacted denatured proteins compared to albumens without this additive. Triethyl citrate plus trisodium citrate had a similar effect but numerous irregular small clumps of medium electron density were evident in this albumen system. Electron dense surface layers of denatured proteins at the air-albumen interface of whipped albumens were much the same without or with additives. Evidence is presented to indicate that sodium hexametaphosphate and trisodium citrate increases foam stability by crosslinking proteins, and triethyl citrate improves foamability by denaturing ovalbumin.