University of South Australia cracks oat oil code to boost milling yields and plant-based potential

New research from the University of South Australia (UniSA) is shedding light on how oil is produced in oats, opening the door for more efficient processing and new applications in plant-based foods and oat flour.

Although Australia is the world’s second-largest exporter of oats, the high oil content of oat grains has long posed a problem for processors. It makes milling less efficient and limits opportunities for product development, especially in fast-growing sectors such as plant-based proteins.

Now, researchers at UniSA, along with collaborators from the South Australian Research and Development Institute (SARDI) and the University of Adelaide, have identified the biological processes that govern oil synthesis in oat grains. Their findings are expected to help breeding programs develop naturally low-oil oat varieties, improving yields and unlocking further value along the oat supply chain.

“While oil can be removed from partially milled oat flakes – using supercritical carbon dioxide prior to further milling – this approach is laborious and expensive,” commented UniSA PhD candidate Darren Lau. “Breeding low-oil oat varieties is a cost-effective approach but requires further understanding of oil production in oats. This is where our research is critical.”

The team used spatial imaging to monitor oil accumulation in two contemporary oat varieties as the grains developed. They then applied advanced ‘omics’ technologies, including lipidomics and proteomics, to map lipid and protein expression. This allowed them to pinpoint key enzymes that influence oil levels and gain a clearer picture of how oil biosynthesis interacts with other grain development processes, such as starch synthesis.

“Our analysis has identified several key enzymes that are involved in oil synthesis which could be genetically manipulated to lower oil content of oat grains,” said Lau. “Reducing oil content could also unlock new opportunities in sectors like oat flour and alternative proteins, which could significantly strengthen Australia’s position in the market.”

These opportunities are considerable. In 2022, global oat production totaled 26 million metric tons, making oats the seventh most-produced cereal. The ability to produce more versatile, low-oil oats could place them in the same category as mainstay grains like wheat, rice, maize and barley — both in terms of volume and value.

The research is already being put to use by the Grains Research and Development Corporation (GRDC), which is working through its oat grain quality consortium to explore how the findings can improve oat suitability for milling and food and beverage ingredient development.

“The consortia are currently working on a larger and more diverse oat cohort to further investigate molecular markers and nutrient partitioning of oil in oats,” Lau said. “They are also investigating one of the key enzymes validated in this study to determine whether manipulating or removing it can lower oil content, and how that affects the growth of the plant.”

SARDI project lead Dr Janine Croser welcomed the findings, calling them “important insights into the biological mechanisms underlying varietal differences of oil production in developing oat grains.”

“We expect that the development of low-oil lines will improve efficiencies in the flour milling process and potentially lead to novel uses for oats,” she said. “With demand for plant-based foods on the rise, we anticipate the oat grain quality consortium research will help put Australia at the forefront of oat innovation – supporting growers, processors, and exporters alike.”

The full research paper, Proteomic and lipidomic analyses reveal novel molecular insights into oat (Avena sativa L.) lipid regulation and crosstalk with starch synthesis during grain development, is now available online.