blemishes from rubbing; and development of accumulations or clusters of the fat and oil
in droplets. The relative viscosity of the albumen has a direct bearing on the accurate
determination of defects on the yolk before the candling light. Unless yolk defects are
very prominent, detection of them is difficult particularly when the egg has a thick
albumen. Germ development is visible before the candling light and can generally be
detected as a circular dark area near the center of the yolk shadow. If blood is visible,
the egg must be rejected as inedible. The terms used to describe yolk defects are:
(1) Practically free from defects--AA and A Quality. A yolk that shows no
germ development but may show other very slight defects on its surface.
(2) Clearly visible germ development--B Quality. Development of the germ
spot on the yolk of a fertile egg that has progressed to the point where it is plainly visible
as a circular area or spot with no blood in evidence. Meat spots aggregating no more
than 1/8 inch (3 mm) in diameter may be present.
(3) Serious yolk defects (SYD)--B* Quality. A yolk that shows
well-developed spots or areas and other serious defects, such as an olive yolk, which
do not render the egg inedible. Small blood spots aggregating no more than 1/8 inch (3
mm) in diameter may be present.
(4) Blood due to germ development. Blood caused by development of the
germ in a fertile egg to a point where it is visible as definite lines or as a blood ring.
Such an egg is classified as inedible.
3-16. THE WHITE
a. Practically all new-laid eggs contain four layers of albumen--chalaziferous,
inner thin, thick, and outer thin. The appearance of the egg before the candling light is
governed largely by the relative proportions of the thick and outer thin layers of
albumen. The white and yolk are very closely associated, and any discussion of either
factor, of necessity, involves the other. However, there are two important
considerations about the white that are included in the standards of quality: condition
(viscosity) and clarity.
b. The condition of the white is determined in candling by the intensity of the
yolk shadow and the freedom of movement of the yolk as the egg is twirled before the
candling light. These factors are related to the viscosity of the white. Thick whites
permit only limited movement of the yolk and an indistinct shadow results.
c. The reverse is true of thin whites, which permit free movement of the yolk and
a distinct shadow results. You, the inspector, must judge from the behavior of the yolk,
how the white will appear when the egg is broken out. The appearance of the albumen
in broken-out eggs is illustrated in figure 3-6.