Smudge Damage (SM)
Smudge is a discolouration on the kernel and is an objective grading factor. The discolouration may be brown, black or red.
The discolouration is assessed as smudge in amber durum if:
- More than one-half the kernel is discoloured, or
- Discolouration of the crease
- Has spread onto the cheeks of the kernel regardless of any discolouration of the germ
- Appears as a thin line extending more than half the length of the crease, in combination with any discolouration of the germ.
The discolouration is as a result of infection by some common field fungi such as Alternaria alternata.
Surface discoloration due to fungi such as A. alternata is not a safety concern. However, it is considered a serious quality defect in durum wheat because it causes dark specks in semolina, which is used to make pasta (Dexter and Matsuo 1982; Dexter 1993).
- Factors affecting processing. The implications of frequently encountered grading factors on the processing quality of durum wheat, by J.E. Dexter and N.M. Edwards, 1998.
- Factors affecting processing performance. The implications of frequently encountered grading factors on the processing quality of common wheat, by J.E. Dexter and N.M. Edwards, 1997.
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