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The implications of frequently encountered grading factors on the processing quality of common wheat



2. Introduction

One of the most important factors determining the processing value of wheat is physical condition (Dexter and Tipples 1987, Dexter 1993). Accordingly, most wheat producing countries have grading and classification systems in place that are intended to assign and preserve the commercial value of wheat parcels on the basis of processing potential, while also satisfying producers by giving the best possible return.

If a wheat grading and classification system is to be meaningful, it must have a scientific basis. In Canada the scientific basis for wheat grading and classification comes from research investigations conducted by the Grain Research Laboratory (GRL) and Industry Services divisions of the Canadian Grain Commission (CGC). These investigations document the effects on wheat end-use quality of grading factors at various levels and degrees of severity, to ensure that Canadian wheat grade tolerances are realistic. This article highlights the results of CGC research on frequently encountered wheat grading factors that affect edibility (ergot, Fusarium head blight) and processing performance (orange wheat blossom midge, hard vitreous kernels, frost damage, sprout damage, heat damage, mildew and smudge and black-point), and assesses the significance of each grading factor on milling and end-product quality.