A specific kernel size, shape and colour is reserved for each wheat
class grown in western Canada (Fig. 23). A requirement for registering a wheat
variety in western Canada is that it must have the visual appearance reserved
for the class for which it qualifies. This unique feature of the Canadian wheat
grading and classification system is referred to as kernel visual distinguishability
(KVD). KVD ensures that wheat classes are easily and cost effectively kept distinct
throughout the handling system. This preserves the unique attributes of each
class; admixing of classes results in a product with less processing value. In
eastern Canada, KVD is a requirement only for registration into the Canada
Eastern White Winter (CEWW) wheat class.
Physical condition is a primary determinant of wheat processing value.
Physical condition is determined primarily by growing conditions. In Canada, wheat
is graded according to grade standards established by the CGC (2003a). The grade
standards are set to mitigate differences in quality year-to-year. The amount
of wheat grading into the top grades will be less in years when
growing conditions are not ideal, but the quality of a given class and grade
must be comparable to previous years (Preston et al., 1988).
Grade definitions are established under the authority of the Canada
Grain Regulations with direction from the CGC. Tables of specifications provide
structure for assigning grades to grains. Specifications include factors such
as minimum test weight, and maximum tolerances for factors such as foreign
material, contrasting wheat classes, damaged kernels and broken kernels. There are
two sets of standards: primary and export. Primary standards are used to grade wheat
upon delivery into grain facilities, including export terminals. Prior to
arrival at terminals, the grading is done by private grain handling companies.
Wheat arriving at terminals is graded by the CGC. The grade assigned to a lot
by the CGC is the basis for payment.
Export standards are used to grade wheat destined for export. The CGC
is solely responsible for grading of export cargoes from terminal facilities.
Some factors such as foreign material and contrasting classes have stricter
tolerances in export standards than for primary standards. Important export
grade standards for Canada Western Red Spring (CWRS) wheat and Canada Western
Amber Durum (CWAD) wheat, the two largest classes of wheat grown in Canada, are
shown in Tab. 17 and Tab. 18. All CGC primary and export standards, definitions
of various types of damage, and methodologies employed by CGC inspectors may be
found in the Official Grain Grading Guide (CGC, 2003a) which is available on
the CGC website at www.grainscanada.gc.ca
Tab. 18:
Tolerances for some Canada Western Amber Durum wheat export grade determinantsa
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Associated with each wheat grade, there is also a specification for
degree of soundness. For example, degree of soundness for No 1 CWRS is defined
as "reasonably well matured, reasonably free from damaged kernels",
for No 2 CWRS it is defined as "fairly well matured, may be moderately
bleached or frost-damaged, reasonably free from severely damaged kernels" and
for No 3 CWRS it is defined as "may be frost-damaged, immature or
weather-damaged, moderately free from severely damaged kernels". These
definitions relate to factors such as frost damage, mildew and degree of
maturity which are difficult to measure objectively. Standard samples are
prepared as visual aids in accessing degree of soundness. The standard samples
are prepared by the CGC every autumn, following the harvest, to reflect the visual
appearance associated with growing conditions from the most recent harvest. The
CGC submits the standard samples for approval to the Western and Eastern Grain
Standards Committees, which are composed of producers, exporters, processors
and scientific and technical specialists. Once approved they are distributed to
CGC offices, and to inspection offices of private grain companies.
An important feature of the grading standards for all western Canadian
wheat classes, and for CEWW in eastern Canada, is variety designation. This
relates to the strict variety registration process in Canada, which will be discussed
in more detail later. The only varieties eligible for the milling grades of
Canadian wheat classes with variety designation are those with processing
quality proven to conform to the quality model established for the class. The
CGC designates which varieties are eligible for each class of wheat. Variety designation
assures that intrinsic quality is the same for all grades within a given class.
Processing quality differences between milling grades then are solely
attributable to grade tolerances, and differences in protein content.
The Canadian wheat grading system has a scientific substructure. The
Grain Research Laboratory (GRL), the scientific branch of CGC, and Industry
Services, the branch of CGC responsible for setting grade standards, investigate
the effects on end-use quality of the grading factors encountered in Canada so that
grade tolerances can be realistically set (Dexter and Edwards, 1998a, 1998b).
The combination of a strict wheat variety registration requirement,
and a grading system with a scientific basis, provide a direct linkage between
the visual appearance and the processing quality of Canadian wheat classes with
variety designation. That linkage, together with KVD, allows the segregation of
Canadian wheat quickly and efficiently according to processing potential.
Throughout loading from a terminal elevator, the CGC continuously samples
and grades the wheat, and officially weighs it. The CGC has a strict loading protocol
that must be followed. At all times wheat must remain within the export standards
established for the grade ordered. When the wheat has been loaded, the CGC
issues a Certificate Final certifying the grade and exact weight of the
shipment. The Certificate Final is the customer's guarantee that if there is a
disagreement concerning quantity or quality of a shipment, the CGC will investigate.
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