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Wheat gluten strength concerns buyers

International buyers still concerned after Canadian wheat showed poor gluten strength in 2012

In 2012, international buyers of Canadian wheat registered complaints about the crop’s poor gluten strength, according to Dave Hatcher, a research scientist with the Canadian Grain Commission. 2013 presented less of a problem, but even into 2014, buyers are still concerned about the overall crop quality.

Several factors impact gluten strength. Weather, variety and growing conditions all interact to have a significant impact. Wheat varieties with excellent intrinsic quality can also be negatively impacted by very high levels of physical damage resulting from midge or fusarium infection, which can drop them to lower grades.

Most importantly, each variety of wheat has a unique genetic makeup, with different gluten protein compositions, says Bin Xiao Fu, a bread and durum wheat research scientist with the grain research laboratory of the Canadian Grain Commission. Different wheat classes with different gluten protein compositions are developed for different applications.

CWRS, Canada’s premier class of wheat, is comprised of a blend of wheat varieties that have varying gluten protein compositions. “A few years ago some lines were registered into CWRS that passed the tests of the registration trials. They barely cleared the bar for gluten strength, but they had no additional room below the bar,” says Hatcher. In 2012, the combination of poor environmental conditions and varieties at the lower end of gluten strength resulted in a lower quality CWRS product overall.

“When the environment has been poor, depending on how much water and heat it gets, and any grading factor that comes into play, the product can drop below the acceptable gluten strength level expected by the buyer,” says Hatcher.

Gluten strength is a key quality trait considered in quality evaluations for variety registration in the CWRS wheat class. “Gluten strength of varieties eligible for registration must be within a range defined by the Prairie Recommending Committee for the Wheat, Rye and Triticale Quality Evaluation Team,” says Fu. “Although the range is relatively narrow for CWRS, variation in gluten strength does exist among registered varieties.”

Historically, says Hatcher, CWRS has been valued by international customers for its high gluten strength — its balance of elasticity and extensibility, which offers bread dough both malleability during processing and the strength to hold up throughout fermentation and baking.

“Most countries normally don’t make a product with 100 per cent CWRS,” says Hatcher. “One of the reasons they buy it is because they know it has an intrinsic, high-quality gluten strength — so they can add 10 to 15 per cent of a lower quality grain as a filler.”

Gluten strength is critical for wheat product processing because every product, from bread to noodles, starts with dough. The physical properties of the dough directly impact processing.

As every baker and processor knows, consistency is key in the baking process. CWRS has until recently been known for its consistency. The lower dough strength of the 2012 crop came as a nasty surprise to Canada’s international customers.

Tests re-introduced

“With respect to quality standards, in February this year we brought the extensograph test back into registration trials because it is the best indicator of gluten strength available,” says Hatcher.

The test was dropped in 1999 because it requires at least two hours to process a single sample, and it requires a large flour sample

“At the time the extensograph test was dropped,” says Hatcher, “the farinograph was the only test remaining for measuring gluten strength, but we’ve subsequently found that it doesn’t discern between varieties’ gluten strength enough,” he says.

Hatcher sees gluten strength as, ultimately, a critical issue for growers. Maintaining gluten strength in CWRS is key to maintaining consistency, and consistency will guarantee the product stays in demand over time. Stringent quality testing requirements will ensure a more consistent product.

“In my opinion, it will allow the grower’s wheat variety a much better chance of being marketed in the international community,” he says. “A couple of years back many of our markets were unhappy with the CWRS and cut back on the amount they were ordering. If we can demonstrate that we’ve cleared that hurdle there will be renewed interest in ordering CWRS.”

The re-introduction of the extensograph test will help differentiate wheat varieties in terms of gluten strength, says Fu. “The new varieties in registration trials will be sufficiently evaluated with the combination of the farinograph and the extensograph, to ensure they meet the needs of the customers for gluten strength.”

The CGC is collaborating with other labs to improve bake methods to better discern differences in baking performance among wheat varieties. The CGC’s bread wheat research team has developed a modified extensograph method which is faster and requires less flour. It has been approved by the Wheat Quality Evaluation Team of the PGDC to be officially used in wheat variety registration trials.

As for this year’s crop, Hatcher believes Canada’s CWRS is in good shape. “We are very optimistic, based upon last year’s shift in variety composition, that we’ll have improvement this year,” he says.

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Julienne Isaacs

Julienne Isaacs is a Winnipeg-based freelance writer and editor. Contact her at [email protected]

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