The Foundation for Food & Agriculture Research (FFAR) has awarded a research grant of over $800,000 to develop a method for determining the amylase activity in wheat that can be used locally, without the costly equipment and specialized personnel currently required. The usual analysis method for determining alpha-amylase activity is based on the Falling Number or Hagberg Falling Number, which involves immersing a wheat flour and distilled water solution in a water bath near the boiling point, stirring the solution for 1 minute to facilitate starch gelation, and measuring the time it takes for a predetermined weight to pass through this gel. The higher the amylase activity, the faster the weight will pass through the gel, resulting in a lower Falling Number value.
As this method requires the use of instruments that are difficult to implement on farms or in silos, and since the Falling Number significantly influences wheat pricing, a rapid method would help farmers and silo operators make quick and informed decisions about wheat quality. Additionally, it would prevent mistakes that could affect the quality of wheat blends in silos or trucks by unknowingly storing grains with high amylase activity. It should be noted that mixing grains with high and low Falling Numbers cannot be done arithmetically; even small quantities of grains with high amylase activity can negatively impact this parameter when mixed with much larger quantities of low Falling Number wheat. This could lead to millions of dollars in losses for the industry.
High amylase activity, and consequently a low Falling Number, leads to the loss of baking properties of flour, resulting in products with abnormal textures that cannot form under usual conditions: sticky, gummy, with large voids, even after baking.
The current test for determining the Falling Number was developed over 70 years ago by Perten. „Every year, farmers hold their breath while waiting to see if their wheat crop passes this test,” said Dr. Angela Records, Chief Scientific Officer of FFAR. „By allowing early detection of the Falling Number, this research saves high-quality wheat from becoming animal feed and saves millions of farmers.”
In addition to developing new rapid tests, the grant includes two other components to assist growers in managing alpha-amylase. The first is the development of an early warning system to alert stakeholders about weather patterns that could cause increases in alpha-amylase. The second involves conducting research to better understand the genetic regulation of alpha-amylase. This will provide researchers with tools to improve wheat varieties that are more susceptible to Falling Number reduction.
In general, alpha-amylase activity is linked to the weather conditions around harvest time. Rain can increase the moisture content of the grains and trigger metabolic phenomena within the kernels that accompany the germination process. As the endosperm, rich in starch from which flour is obtained, is responsible for providing the glucose needed for the nourishment of the embryo of the future plant, the synthesis and activation of these enzymes accompany germination processes. More recently, a situation has been identified in which wheat amylase activity can increase in the absence of the aforementioned conditions. This is known as late-maturing amylase activity and is triggered by genetic factors present in certain wheat genotypes under specific environmental conditions (generally low temperatures during the kernel maturation period). Although the activated alpha-amylase in wheat under these conditions results in a lower Falling Number in the wheat flour, it has not been correlated with quality defects in white flour or baked products derived from it. The explanation is based on the fact that alpha-amylase is localized in the aleurone layer of the kernels, a layer located at the interface between the bran and endosperm and is only partially present in white wheat flour, with the majority being removed along with the bran.
