Effect of Freezing - Thawing and Stabilizers on the Phase Behavior of Egg Micro - Particles and Quality Attributes of Liquid Egg

Abstract

Freezing can adversely affect the quality of liquid egg through co mplex inter - particle interactions of egg micro - particles. The effect of pectin, PG - Alginate (PGA), Arabic Gum, maltodextrin and defrost temperature on the rheological properties, microstructure and color of frozen egg was studied. The fresh sample exhibite d a light yellow color with high values of L and positive values of a and b . Freezing resulted in a reduced L value with slight changes in a and b. The additives could enhance the lightness with the closest values of L to that of the fresh sample detected for PGA and pectin. Fresh egg with a low viscosity exhibited near - Newtonian flow behavior. However, the freezing - thawing significantly increased the viscosity. Accordingly, the flow behavior index of the frozen samples was decreased significantly along wit h a sharp increase in the consistency index, revealing a pseudo - plastic behavior. All frozen samples exhibited higher viscosities than the fresh sample. Fresh samples contained evenly distributed micro - particles ranging from 0.05 to 5.50  m centering at 1. 27  m. Freezing resulted in aggregated particles with significantly larger sizes. Maltodextrin significantly reduced the particle size. Further reduction was achieved by the addition of pectin, PGA, and Arabic gum. Smallest particle size distributions were achieved at pectin and PGA concentrations of 0.25 and 0.1%, respectively. The results of this study can be employed for the development of new products based on frozen egg with no added sugar or salt, while maintaining the physical and functional properti es of the final product. Keywords : Arabic gum, Flow behavior, Microstructure, Pectin , PG - Alginate .