20 kHz Ohmic heating vs. conventional thermal treatment: Comparison of functional and physical properties of liquid egg white and yolk

Abstract

The effects of stationary and agitated ohmic heating (OH) methods and conventional thermal pasteurization method (water bath) on changes to liquid egg white and yolk properties (color, albumen turbidity, viscoelasticity, foaming, and emulsify abilities) were evaluated. The degree of thermal protein denaturation (TPD) was also analyzed for quality evaluation. Changes to processed egg samples in color and albumen turbidity (egg white only) were negligible (ΔE* < 3), which are not noticeable to the naked eye. Viscoelasticity of all pasteurized eggs also showed no significant differences (p > 0.05) compared to raw eggs. The foaming abilities of egg white and the emulsifying abilities of egg yolk were considerably enhanced, particularly under agitated OH. Agitation during the OH pasteurization process showed great potential due to its superior maintenance of liquid egg quality compared to the other methods. These results confirmed the quality retention obtained using high frequency OH treatments and provided theoretical guidance for the design of OH-able liquid egg products.