Don’t Blend Sprout-Damaged Wheat with Sound Wheat

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Cereals Canada and Canadian International Grains Institute (Cigi) would like to remind producers about the tight tolerances for sprouted kernels and to avoid blending sprouted wheat with sound wheat.

Sprouting is one of the main grading factors in the 2019 wheat harvest. Tight grading tolerances for severely sprouted kernels and total sprouted kernels in wheat help protect quality for millers and end-product processors.

Even small amounts of sprouted wheat can negatively affect flour quality for baking and grade standards have been established to reflect this. It may be tempting to blend in some lower grade wheat but you run the risk of costly downgrading.

Sprouting occurs under conditions of prolonged dampness or rain when the wheat is at maturity. Germination begins when mature kernels absorb water and produce enzymes that break down stored starch and protein in the endosperm. This can happen when the wheat is still standing in the field or when it is lying in the swath.

Germination produces an enzyme know as alpha-amylase which breaks down starch in the kernel. Although some alpha-amylase is present in sound wheat kernels, the enzyme is produced, and its activity increases at an accelerated rate during germination. The alpha-amylase activity of a severely sprout damaged kernel would be significantly higher than the alpha-amylase activity during the early stages of germination. A wheat sample containing very low levels of sprouted kernels may exhibit high alpha amylase activity, meaning the kernel may show little to no visual evidence of sprout damage but alpha-amylase activity can be high.

In breadmaking, alpha-amylase reduces the water-holding capacity of flour, reducing the number of loaves of bread obtained from a given weight of flour. It also causes the bread dough to be sticky which results in processing challenges in the bakery, and bread that has a coarse crumb structure (lots of holes) which is also gummy, difficult to slice and package. In certain types of Asian noodles, noodle colour can be negatively affected.

The tolerances for sprout-damaged kernels in CWRS1 wheat are:

SPROUTED
Grade nameSeverely Sprouted (%) Total (%)
No. 1 CWRS 0.1 0.5
No. 2 CWRS 0.2 1.0
No. 3 CWRS 0.3 3.0

1 Official Grain Grading Guide (Primary Grade Determinant Tables)

Some companies are augmenting grading of sprout damage with Falling Number (FN) testing. FN testing is not part of the Official Grain Grading Guide but can be included in sales contracts. FN provides an indication of the level of alpha-amylase in a wheat sample and is standard in many international contracts.

CGC and Cigi staff will be advising customers on how to work with sprout damaged wheat during the new crop seminars.  

For additional details on sprout damage, please refer to the Canadian Grain Commission website at:
https://grainscanada.gc.ca/en/grain-quality/grain-grading/grading-factors/grading-factors-wheat/sprout-damage.html

Cigi Contact:
Lee Huscroft
Phone: 204.983.7784
lhuscroft@cigi.ca
Cereals Canada Contact:
Brenna Mahoney
Phone 204.942.2166
bmahoney@cerealscanada.ca