Gene-edited wheat unlocks low acrylamide levels for flour

15 Feb 2023 --- The level of acrylamide continues to spark debate in the food industry as UK wheat trials of a gene-edited (GE) wheat variety discover a “significant reduction of the potential carcinogen acrylamide when the flour is baked.” The initial findings could have a considerable impact as low acrylamide would allow food businesses to get ahead of the curve on evolving regulations on the presence of acrylamide in food without costly changes to production lines or reductions in product quality.

Speaking with FoodIngredientsFirst, professor Nigel Halford, who led the trial conducted by Rothamsted Research, explains just how important a breakthrough the initial findings could be and how a second trial, producing even lower levels of acrylamide in another wheat variety, is underway.

“Legislation introduced in 2017 by the EU set “benchmark levels” for the presence of acrylamide in food products, as well as setting out compulsory mitigation measures. If a product is over the benchmark, the manufacturer must review the measures they are taking to keep acrylamide levels low,” he says.

“However, the EU will publish a paper this month setting out its intention to set “maximum levels” for some products, including, we believe, every cereal product: bread, biscuits, breakfast cereals, snacks, etc.”

“If a product is over a “maximum level,” it will be pulled from the shelves by retailers, so complying with those regulations will be crucial. Wheat with 50% less asparagine in the grain (which is what we see in the CRISPR wheat in the trial) would make it much easier for food manufacturers to do that.”

“Of course, we don’t know if the UK government will follow suit, but the big food manufacturers operate in a trans-European way in any case.”

Lower asparagine
Acrylamide is present in food following formation from the naturally present substances free asparagine (amino acid) and sugars during high-temperature processing, such as frying, roasting and baking.

The new wheat strain used CRIPSR gene editing to lower the asparagine formation in the wheat grains. When cooked, this amino acid is converted to acrylamide – a potential carcinogen that food processors are keen to control.    

The field trial results show a significant acrylamide reduction when the flour is baked. Once ground into flour and cooked, the amounts of acrylamide formed were reduced by up to 45%.

Levels of asparagine (acrylamide’s precursor) in the GE wheat were up to 50% lower than the control variety Cadenza. 

Levels of asparagine in the GE wheat were up to 50% lower than the control variety Cadenza.Testing viability
The field trial determined whether the new GE wheat would be viable. Indoor trials under glass had proved successful, but only by planting out in experimental fields could the research team be sure that the new strain could deliver for farmers. 

“This is the first time the wheat has been grown in the field. The trial showed that the low asparagine characteristic was maintained in the field and that there was no significant effect on yield or protein content. Breeders and farmers will only believe data that is generated in the field because results under glass do not always translate to results in the field,” prof. Halford details.

Even lower acrylamide
A second wheat trial could identify even lower levels of acrylamide, prof. Halford reveals.

“The second field trial is underway and this includes wheat with a second gene knocked out. That wheat should be even lower in asparagine. We also have some GM-free plants from that line - the CRISPR process involves a GM step, but once the edit is made, the GM component can be removed by standard plant breeding methods,” he explains.

“These plants qualify as Precision Bred Organisms under the legislation currently in the final stages of its passage through Parliament (royal assent expected next month), so in theory, could be commercialized.”

However, he points out that this will depend on breeders’ confidence in the new legislation. It would still take five to ten years for breeders to cross this new wheat into their breeding programs and produce a commercial variety.

Gene editing bill in Parliament
The trial results are timely as the Genetic Technology (Precision Breeding) Bill, which will make provision for the release and marketing of GE crops, is in the final stages of its passage through Parliament.

The Bill covers precision-bred plants and animals developed through techniques such as gene editing, where the genetic changes could have occurred naturally or through traditional breeding methods. This differs from genetic modification (GM), which produces organisms containing additional genes.It would still take 5-10 years for breeders to cross this new wheat into their breeding programs and produce a commercial variety.

Alternatives in acrylamide and acrylamide-reducing solutions have mounting potential in global markets.

However, there are still some regulatory hurdles to consider.

Global regulatory frameworks
The US Food & Drug Administration monitors acrylamide levels in certain foods in the US because “of its potential to affect human health.” 

“Although it’s not clear exactly what risk acrylamide poses to humans, the FDA has recommendations for both consumers and industry about how to reduce acrylamide formation in foods,” the FDA says.

In 2016, the agency developed a “Guidance for Industry” that outlines strategies to help growers, manufacturers, and foodservice operators reduce acrylamide in the food supply.

Meanwhile, EU legislation came into force on April 11, 2018, concerning the amount of acrylamide in foods with “benchmark” levels being set for various products. The law limits the amount of acrylamide allowed in packaged foods and forces manufacturers to closely examine and reduce acrylamide levels in products.

By Gaynor Selby