Midge damage (MDGE DMG)
Midge damage is defined in the Official Grain Grading Guide.
For grading purposes, midge damaged kernels must have at least two of the following characteristics;
- A rupture of the bran on either the back or side of the kernel
- A distinct white line or mark, located on the back or side of the kernel
- The kernel is distinctly distorted
Procedure for assessment
Midge damage is an objective grading factor.
To assess midge damaged samples, the inspector performs a physical separation to assess the percentage of these damaged kernels in the sample. The number of grams utilized to perform the assessment is predetermined and defined in the Official Grain Grading Guide. The inspector will then apply the tolerances for midge and sawfly as set out in the Grade Determinant Tables found in the Official Grain Grading Guide.
The Orange blossom wheat midge (Sitodiplosis mosellana) (Government of Alberta, Alberta Agriculture, Food and Rural Development) causes midge-damaged kernels. This pest is found in wheat-growing areas of Europe, Asia and North America. The orange fly deposits its eggs on the floret and then the hatching larvae feed on the developing grain.
The shrunken distorted grains reduce flour yields and produce dark flours with increased flour ash. Seriously midge-damaged wheat exhibits weak, sticky dough properties; low baking absorption and poor bread quality. Protein content is abnormally high, but gluten protein quality is distinctly inferior.
Midge damage has a serious effect on durum wheat semolina milling performance. As midge damage increases, semolina refinement (ash content, color and speck count) declines and pasta can became less bright and undesirably brown.
More information on the affects of midge damage on processing is available in Grain Research Laboratory papers on factors affecting processing performance of common wheat.
Review the following pictures and identify which kernels you would consider midge damaged. Continue scrolling down to find the answers.
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