Researchers on Hunt for Strategies to Address Pecan Allergens

Although pecans are rich in heart-healthy omega oils, proteins, carbohydrates and essential nutrients, a part of the American population is unable to enjoy their wholesome benefits. Scientists estimate that tree nuts can trigger allergic reactions in about 1 percent of Americans, according to research published in the Journal of Allergy and Clinical Immunology.

What if something could be done to remove the dangers of nut allergens? Progress is being made in exciting studies underway at the U.S. Department of Agriculture’s Agricultural Research Service (ARS) and similar institutions across the country.

Food and nutrition scientists hope to shed light on the origins of the specific substances found in tree nuts that are believed to trigger allergic reactions. Several researchers also want to know when and how these substances appear during nuts’ natural growth cycles and what, if anything, farmers might do differently to mitigate their effects or potency.

Armed with this knowledge, it may eventually be possible for pecan growers, agriculture scientists or food manufacturers to either eliminate allergens from pecans using special cultivation techniques or to introduce a food processing method that greatly reduces the effects of allergens.

Chris Mattison is a molecular biologist specializing in food processing and sensory quality research for the ARS in Louisiana. Since 2010, he and his team have taken a close look at three proteins – 2S albumin, 7S vicillin, and 11S legumin – that have been identified as allergens in pecans and other tree nuts.

In 2012, Mattison and a group of colleagues published a study in the Journal of Horticultural Science & Biotechnology showing pecan trees typically express these allergen genes late in the summer as the edible nut forms. His data show that expression of allergen genes peaks in early- to mid-September, depending on the variety of pecan.

“This was one of the first studies to try and understand what’s going on with protein production when a tree builds a nut,” Mattison says. “Right now we have research underway that takes an even broader look at the same process.”

This was one of the first studies to try and understand what’s going on with protein production when a tree builds a nut

As Mattison and other scientists develop a deeper understanding of the chemistry of protein production in pecans, it may eventually be possible for them to identify agricultural techniques that target and regulate the genes that cause allergen proteins to accumulate in nuts.

“Understanding the timing of allergen gene transcription could assist plant breeders in the development of cultivars with lower levels of allergens,” he says. “It may be possible in the future to reduce or eliminate the allergens as pecans mature. If we can find methods to reliably alter nut allergens significantly, it could lead to a much safer nut for many consumers.”

Efforts to identify and mitigate allergens in tree nuts have been underway for many years, and scientists have learned volumes about the different proteins found in nuts.

“But while they are different on some levels, there are characteristics that help us identify them as allergens,” Mattison says. “An open question for many of us is why specific proteins from tree nuts produce an allergic reaction in some consumers, when similar proteins in other foods don’t appear to cause issues with the same frequency.”

If research findings support the possibility, how long might it take to bring an allergen-free variety of pecan to the market?

“It would take years to decades,” Mattison says, but the benefits could be tremendous.

“The United States is number one in pecan production and has been for a very long time,” he says. “At some level, this type of research will benefit the pecan industry and consumers alike.”

Above is a video of Chris Mattison presenting some of his findings at an industry conference.