Relationship between the functional properties of commercial dried albumen products and their protein composition and thermal denaturation

The processes for producing dried albumen can deeply affect the foaming and gelling properties of the final product due to the different thermal treatments and other technological practices applied. Twenty one samples of commercial powder/flake/granule albumen products were analyzed in this study to investigate the relationships between the composition and denaturation of albumen proteins and the foaming and gelling properties of the products. The HPLC protein patterns and the amount of total and surface SH groups were quite different among the egg product samples. The amount of surface SH were directly correlated with most of the variables that measure the formation of a good gel structure and inversely correlated with the volume (overrun) and consistency of foam. Ovalbumin denaturation improved the gelling properties while reducing the foaming ones. The presence of undenatured ovomucoid, conalbumin, and lysozyme reduced the gelling properties, whereas a high lysozyme content enhanced foam consistency and stability. The results of the study indicate that protein denaturation of albumen dried products favors the formation of stronger gels, while hindering the foaming properties.