Scientists at UK-based Rothamsted Research have developed gene-edited wheat with substantially reduced levels of free asparagine, a precursor to acrylamide. The success was demonstrated through two years of food trials and was published in Plant Biotechnology Journal.

Free asparagine is an amino acid that converts to acrylamide, a toxic compound and probable carcinogen formed during high-temperature cooking processes such as baking, frying, and toasting. The researchers reported that CRISPR/Cas9-edited wheat lines achieved reductions in free asparagine of 59 percent, and up to 93 percent in a dual-edited line targeting both the TaASN2 and TaASN1 genes. Yield was not affected in the edited lines.

Wheat with the promise of reduced acrylamide formation could improve food safety for consumers and help producers ensure compliance with evolving regulatory requirements.

Study Design

Field trials were conducted using Triticum aestivum cv. Cadenza, with gene edits targeting TaASN2, a gene expressed primarily in developing seeds. Additional edits to TaASN1 further reduced asparagine levels. The researchers reported that total seed nitrogen, an indicator of protein content, was not affected.

Impact on Acrylamide Formation in Food Products

The reduction in free asparagine translated to significantly lower acrylamide levels in finished products. Bread made from one CRISPR-edited line showed acrylamide concentrations below detectable limits, while other edited lines maintained levels between 8 percent and 23 percent of control samples after toasting.

Biscuits produced from the dual-edited wheat showed a 93 percent reduction in acrylamide compared to controls.

Comparison with Traditional Breeding Technique

The study also evaluated wheat developed using chemical mutagenesis (TILLING). While TILLING lines achieved a 50 percent reduction in free asparagine, they experienced a yield penalty of nearly 25 percent. Researchers attributed this to unintended mutations associated with the method, highlighting the precision advantage of targeted gene editing.

Regulatory and Industry Implications

The findings come amid increasing regulatory pressure on acrylamide in food. For example, Regulation (EU) 2017/2158 currently sets benchmark levels for the compound in food, and additional maximum limits are expected to come as soon as this year. These requirements apply not only to EU member states, but also to international trading partners.

The UK Food Standards Agency (FSA) is also considering data on the presence of acrylamide in food to support potential policymaking decisions based on the health risks posed by dietary exposure to acrylamide.

The researchers stated that low-asparagine wheat could help food manufacturers meet evolving acrylamide limits without requiring major changes to processing or product formulations. The work also aligns with the UK’s Genetic Technology (Precision Breeding) Act 2023, which established a regulatory pathway for certain genome-edited crops.

Study Context and Limitations

The authors noted that acrylamide formation depends on multiple factors beyond raw material composition, including processing conditions and formulation. However, strong correlations were observed between reduced free asparagine in grain and lower acrylamide formation in tested products.

The study concluded that gene editing offers a viable approach to producing wheat with consistently low asparagine levels, potentially enabling food producers to reduce consumer exposure to acrylamide while maintaining product quality and yield.