WITH legumes becoming big business across northwest Victoria, the latest research out of Monash University is ringing some alarm bells for local croppers.
The research reveals poor storage conditions are causing avoidable quality decline across the legume supply chain – costing growers and processors.
After harvesting, legumes are often stored in bulk silos or on-farm sheds where they can be exposed to hot Australian summers with little or no temperature or humidity control.
High temperatures and humidity during storage trigger internal damage in faba and adzuki beans, making them harder to cook, less nutritious, and less suitable for processing (e.g. canning or protein extraction), the research has found.
In a series of studies published in Carbohydrate Polymers, Food Hydrocolloids, and Food Bioscience, researchers found storing faba and adzuki beans at high temperatures (above 40 °C) and humidity levels (more than 80 per cent) triggers internal changes in the beans’ protein, starch, and lipid structures.
According to lead author Associate Professor Sushil Dhital, how beans are stored after harvest can make or break their final quality, even if they were grown and harvested perfectly.
“There’s a perception that once beans are harvested, the job is done,” Associate Professor Dhital said. “But we found poor storage conditions can quietly ruin bean quality and undo months of good work in the paddock.
“We saw even perfectly bred and harvested beans can develop serious quality issues if not stored correctly.
“Beans stored at high temperatures and humidity become structurally resistant to water absorption and much harder to cook. Their protein and starch are different to those of freshly harvested.”
Known as the HTC defect – hard to cook – it means beans take longer to soften, are harder to digest, and can develop off-flavours.
Associate Professor Dhital said this has real implications for food manufacturers, canning companies, and exporters who rely on consistent, high-quality product.
Australia is one of the world’s top producers and exporters of legumes, yet postharvest handling remains relatively overlooked.
The research team highlighted the need for investment in temperature and humidity-controlled storage systems, along with policy support to ensure the preservation of postharvest quality.
They’re calling for greater industry awareness – particularly from the Grains Research and Development Corporation, which funds research to improve Australia’s grain productivity and sustainability – regarding the impact of storage on bean quality.
“Millions are invested in breeding better beans and improving agronomy,” Associate Professor Dhital said.
“But without proper storage, much of that value is lost. We need a shift in focus from paddock to postharvest.”
