b. As egg quality is unstable and grading procedures are largely subjective, it is
necessary to provide tolerances in grades for small percentages of eggs of a quality
lower than that comprising the major part of the grade. The tolerances are provided to
allow for errors in judgment, errors in the sample, differences in interpretation, and
normal deterioration in quality from the time of grading during a reasonably short period
until the eggs are sold to the consumer.
GENERAL QUALITY FACTORS
a. Quality may be defined as the inherent properties of a product which
determine its degree of excellence. Those conditions and characteristics which
consumers want and for which they are willing to pay are in a broad sense factors of
quality. The quality of an egg is determined by comparing a number of factors. The
relative merit of one factor alone may determine the quality score of the egg,since the
final quality score can be no higher than the lowest score given to any one of the quality
b. Standards of quality have been developed as a means of classifying
individual eggs according to various groups of conditions and characteristics that
experience and research have shown to be wanted by consumers and for which they
are willing to pay. Grades differ from standards in that they provide tolerances for
individual eggs within a lot to be of lower quality than the grade name indicates.
c. Quality factors may be divided into two general groups: Exterior quality
factors, apparent from external observation; and interior quality factors, which involve
the contents of the eggs. Interior quality factors may be determined by candling or by a
flock selection method based on breaking out a small number of eggs from each flock.
CLASSIFICATION OF EXTERIOR QUALITY
a. The external factors of the egg--color, shape, soundness, and cleanliness of
the shell--can be determined without using the candling light, but soundness of shell
should be verified by candling. The method or place where this is accomplished may
vary with the type of candling operation used. In hand candling operations, the
examination for shell cleanliness and color and the removal of Leakers or dented
Checks and misshapen eggs will be accomplished by using the case light.
b. In mass candling operations, the segregation for these shell factors is quite
often the responsibility of the person who transfers the eggs onto the conveyor or
"feeds" the machine. This should be done in a well lighted area. One exception would
be the color segregation, which may be performed either at this position or at the
packing station. This would largely depend on the type of pack desired and whether or
not the machine is of the automatic packing type or if this operation is accomplished by
c. The shell of an egg is judged on its shape, soundness, and cleanliness.