Crop weed may cause gluten reaction

29th July 2021 | Eativity editors

New research has identified proteins in a common weed which could wreak havoc for Australian farmers growing gluten-free crops such as millet, buckwheat and sorghum, and people suffering from gluten intolerance who eat foods made from these crops.

The gluten-like proteins found in ryegrass could be mixing with crops commonly used as gluten-free products or wheat replacements, causing a reaction among people with coeliac disease or gluten intolerance. The work, led by Edith Cowan University (ECU) and Australia’s national science agency, the CSIRO, identified the proteins in 10 cultivars of ryegrass, a costly and invasive family of weeds commonly found in Australian cereal crops.

Gluten-free grains such as buckwheat may cause a reaction if grown near ryegrass weeds.

Researcher Dr Sophia Escobar-Correas says the team has identified 19 proteins found in ryegrass which have similar properties to gluten proteins.

“We’ve developed a method to detect these ryegrass proteins that allows us to distinguish them from other grains,” she says. “While they aren’t strictly defined as gluten, they have the potential to trigger reactions for people with coeliac disease or a gluten intolerance.”

This research helps understand whether ryegrass might be a problem so science can start to determine the impact it might – or might not – be having and devise solutions that give the best outcomes if it is. Dr Escobar-Correas says the next step is to undertake clinical studies to investigate whether these proteins trigger a coeliac response.

“If these proteins cause a reaction, then it’s important that we develop tests to detect their presence in food products which are otherwise gluten-free,” she says.

Wimbledon courts are sown with perennial ryegrass to improve durability.

Professor Michelle Colgrave from ECU and the CSIRO was a co-author on the research and says it has identified an important potential challenge for gluten-free products.

“In 2019, the global market for gluten-free foods was worth around $6.3 billion and its growth shows no sign of slowing,” she says. “This research will help give consumers and producers confidence that products labelled as gluten-free are free from other proteins which may trigger reactions resulting from agricultural co-mingling.”

The WA Department of Primary Industries and Regional Development defines a close relative of the species studied in this project, annual ryegrass, as one of the most serious and costly weeds across Southern Australia. Several cultivars of ryegrass are used as feed for livestock and are commonly used as a turf for sports pitches, particularly winter sports – ryegrass is famously the grass of choice for tennis courts at Wimbledon.