Popcorn: a microbiome-boosting superfood in disguise

Through a decade-long project supported by Conagra Foods, a University of Nebraska-Lincoln research team led by David Holding has naturally bred new varieties of popcorn to outperform other kernels in intrinsic nutritional value and taste.

“When we took on this challenge, I was 50% confident that we could deliver on improvements in terms of nutrition,” Holding said. “But at no time did I think this would lead us to a level of success that also delivered improved taste, texture and prebiotics over conventional popcorn.”

The Nebraska-made varieties — which are currently being tested by Conagra — are claimed to offer nearly twice the level of lysine, an amino acid essential in the diets of humans and livestock, compared to popular popcorn varieties and other cereal grains.

Holding said higher lysine can enhance nutritional value, thus increasing economic value and broadening the appeal of the popcorn.

Dent corn, a global crop and the signature variety in the US Midwest, is said to be deficient in lysine. In the 1990s, researchers successfully bred a gene variant known as Opaque-2 into dent corn, which allowed for a rise in lysine and another essential amino acid, tryptophan. The resulting variety, known as Quality-Protein Maize (QPM) has since been used to help combat malnutrition in many developing countries.

With the support of Conagra Foods, Holding attempted to do the same in popcorn; however, he labelled it as “really difficult” to achieve. Popcorn containing Opaque-2 wouldn’t pop, as it tended to turn its hard, glossy kernels into softer, chalkier forms resistant to popping.

Agronomists had managed to breed the softness trait out of the QPM dent corn, but they did so without knowing which genes helped restore the kernels’ glassy consistency.

Holding devoted considerable time to identify the corn genome responsible for restoring that glassiness and set out to cross-breed multiple generations of the QPM dent corn with popcorn varieties selected to contain the restorative genes.

The outcome was high-lysine Quality Protein Popcorn (QPP) that pops as well as the original variety.

“When this project started, I wasn’t sure we could achieve that, given that people hadn’t been very successful in transferring beneficial traits from dent corn to popcorn in the past,” Holding said. “We’re the first to take the dent QPM variety and successfully convert that into popcorn, achieving high lysine and maintaining popping.

“This is a product that lends itself to organic production and can be marketed as a novel popcorn variety, as consumers are paying more attention to their foods’ nutritional value. For popcorn breeding in general, this also shows the potential for mining other traits from dent corn into popcorn to improve the crop’s agronomic performance.”

In other advancements, a blind taste testing saw many of the QPP hybrids outperforming the non-QPP lines in taste and texture, and work with the Nebraska Food for Health Centre is being done to show positive prebiotic impacts of the popcorn.

“What we’ve developed here is a complete protein snack that can be marketed as a superfood due to its positive prebiotic qualities,” Holding said. “And it isn’t just a snack food. It is also quite nutritious and could be beneficial as a dietary supplement in developing countries where protein is needed.

“This work has truly been much more successful than we expected.”

Image caption: iStock.com/ChamilleWhite