Viscosity of egg white from hens of different strains fed with commercial and natural additives

Abstract

Yolk color and egg white (albumen) cleanliness and viscosity are important parameters by which consumers judge the quality of eggs. This study aimed to investigate changes in albumen viscosity during storage of eggs for up to 36 days from two different commercial laying hen strains (Carijo Barbada and Isa Brown) fed a diet containing annatto (1.5 and 2.0%) or a synthetic additive without synthetic colorants (control). Analyses of humidity, albumen height, pH, viscosity, foam formation, and stability were carried out on eggs. Carijo Barbada strain had smaller albumen, lower humidity and higher egg white viscosity than Isa Brown strain; however, with storage, viscosity lowered significantly on both strains. Initially, the addition of 2.0% of annatto or a synthetic additive increased viscosity in both strains, but with storage only the control maintained longer viscosity. Lower viscosity did not change foam density and stability.

Ozone treatment of shell eggs to preserve functional quality and enhance shelf life during storage

“…Thick albumen progressively liquefies and thins with time, transforming itself into thin albumen due to the changes in the complex lysozyme–ovomucin. Any adverse effects on the viscosity of albumen affect these properties and would make eggs unsuitable for industrial use . Albumen viscosity may be used as a tool for assessing egg quality, in that the gelatinous structure of thick albumen changes physical and chemical characteristics and gradually breaks down into a clear liquid losing its consistency during storage.…”

“…For treated eggs, albumen viscosity values decreased to 6.78 and 6.04 (6 ppm), 6.99 and 6.43 (4 ppm), and 7.64 and 6.78 (2 ppm). The albumen viscosity depends on the ovomucin–lysozyme complex . When lysozyme is present in the complex, it becomes stronger and its destabilisation changes due to pH increase during storage .…”

“…The albumen viscosity depends on the ovomucin–lysozyme complex . When lysozyme is present in the complex, it becomes stronger and its destabilisation changes due to pH increase during storage . The liquefaction of albumen occurs because of the increasing of pH.…”

Maintaining functional properties of shell eggs by ultrasound treatment

“…The albumen that surrounds the yolk, which is the thick albumen, progressively liquefies and thins with time, transforming itself into thin albumen due to the changes in the lysozyme–ovomucin complex caused by the increase of pH during the storage. Any adverse effects on the viscosity of albumen will affect these properties and would make eggs unsuitable for use in the food industry and reduce the shelf life of the eggs . During storage, the physical and chemical characteristics of the gelatinous structure of thick albumen change and gradually break down into a clear liquid, losing consistency.…”

“…The viscosity of the albumen decreased during storage, during which a decrease in viscosity was observed, confirming earlier results obtained by Kannan et al and Kemps et al The albumen viscosity depends on the ovomucin–lysozyme complex. When lysozyme is present in the complex, it becomes stronger and its destabilisation is due to a pH increase during storage . The liquefaction of albumen due to the increase in pH is influenced by the ovomucin–lysozyme complex, which leads to changes in viscosity of the albumen during storage .…”