Growers in the United States Pacific Northwest were faced with lower prices for wheat due to limitations in the data provided by the Falling Number test, resulting in millions of dollars lost in the area's 2016 harvest.
The Falling Number test is the most common tool used internationally to measure amylase, a starch-degrading enzyme, in wheat. In the United States a strict, 300-second Falling Number standard is imposed in evaluating wheat quality. If tested grain has a Falling Number below 300 seconds, the grain's price is automatically reduced, in turn reducing farmers' income.
An article published in the AACC International journal Cereal Foods World, Vol. 63, Number 1, titled "Low Falling Numbers in the Pacific Northwest Wheat Growing Region: Preharvest Sprouting, Late Maturity Amylase, Falling Number Instrument, or Low Protein?" and written by Art Bettge of ADB Wheat Consulting, examines how evaluating wheat quality based solely on Falling Number test results can lead to inaccurate assumptions about quality and catastrophic economic effects for growers.
For starters, "the grading system's use of a fixed number to determine quality of a grain lot may falsely downgrade a perfectly good grain lot due to nothing more than unavoidable instrumental variation," said Bettge. In addition, the composition of some grain varieties grown in the Pacific Northwest may cause undesirable—and inaccurate—test results, and a narrow set of environmental factors can activate late maturity amylase (LMA), caused by a genetic defect that is difficult to screen for in breeding programs and can cause unexpected low Falling Numbers. Moreover, grains that fall below the U.S. Falling Number standard aren't necessarily unsuitable for all wheat products.
Fortunately, there are multiple solutions to the problem. Bettge suggests that grain grading standards should be reexamined, particularly as they relate to pricing grain lots. Evaluators and regulators should also take into account the possibility of instrument variation.
"The upshot of using one test, the results of which are used in grading to produce a yes-or-no value at a somewhat arbitrary cut-off point, does a disservice to the grain growers and does not completely reflect the true end-use potential or economic value of a crop," says Bettge. "Understanding sources of variation implicit in a test are as important as the result itself."
Bettge also suggests that more research is needed to better understand the causes, mechanisms, and implications of LMA and the presence and function of waxy grains.
"Over-reliance on only one parameter relating to wheat quality and not knowing the nuances associated with the measurement technique may have consequences of limited profitability or even economic loss, as was demonstrated recently by interpretation of data from the Falling Number Test," said Cereal Foods World guest editor Padmanaban Krishnan, of South Dakota State University. "Art Bettge's article underscores the need to place such measurement within proper context, particularly in decision-making that may have economic implications for affected parties."
"Low Falling Numbers in the Pacific Northwest Wheat Growing Region: Preharvest Sprouting, Late Maturity Amylase, Falling Number Instrument, or Low Protein?" is open-access availalbe for a limited time.
