Chemical free breakthrough in post harvest treatment

Story Added : 19th April 2011

The team, led by Department of Agriculture and Food scientist YongLin Ren, has won the prestigious Cooperative Research Centre for National Plant Biosecurity (CRCNPB) Science Exchange award for ‘Impact on Industry’.

Associate Professor Ren said the team had developed the low oxygen technology as a practical, cost effective commercial alternative to phosphine fumigation for the treatment of grain and as a replacement to phosphine for management of insect resistance.

The project, undertaken in collaboration with farmers and grain companies, is part of a CRCNPB project on low oxygen technology for alternatives to phosphine.

“The low oxygen technology is achieved by purging the stored grains with a high concentration of pure nitrogen. This nitrogen is readily sourced from the air as nitrogen constitutes 78 per cent of air,” Associate Professor Ren said.

“What is most exciting is that the process provides the grains industry with a viable chemical-free treatment and is a low cost alternative to the use of phosphine.”

Associate Professor Ren said through funding from the CRCNPB, field trials were complete, and the team was now working on systematic laboratory studies and on generating protocols for end users.

“A Lake Grace farmer who assisted with field trials is now attracting better prices for his grain after it underwent long-term safe storage of wheat and canola with the chemical free process,” he said.

“CBH is also using the process at grain storages in Perth and Albany. That is significant and is further building the reputation of Australian grain to offer residue-free grain to the international market.”

Associate Professor Ren said the Australian Quarantine and Inspection Service (AQIS) had nil tolerance to insects in exported grains.

“This alternative, using low oxygen technology, provides an economical and chemical free way to replace phosphine fumigation. It also ensures our grain, utilising this new chemical free process, is more attractive to those national and international markets that want insect free grain,” Associate Professor Ren said.

The project is the first of its kind internationally, and has been supported by detailed research on the effects of low oxygen on insect pests, grain in storage and grain quality.

“Internationally, it is a significant breakthrough for biosecurity across the grains industries and we are attracting a lot of interest from overseas,” he said.

“Both Canada and China have sent delegations to WA to look at what we are achieving in terms of insect control in on-farm storage facilities, and we are now in collaboration with Chinese scientists to further develop the efficiency of the membrane separation process for generation of nitrogen and its recirculation through storage facilities.”

Work was also undertaken with canola, which is stored under high temperatures.

“Canola seed colour, oil content and level of free fatty acid did not change during the two month storage period at 30-36°C and 97 per cent nitrogen, while the treatment of canola significantly contributed to insect control and its safe storage by inhibiting the respiration process that can lead to rapid localised heating,” he said.

“We also hope to apply the technology with malting barley and pulses, for control of insects and maintaining colour as well as improving both malting and brewing quality.”

The project had multiple benefits to plant biosecurity including control of insects, food security, residue free grain, a safer workplace and protection of the environment.