Research to push quality beyond the average

Queensland researchers are seeking to better understand the elements of grain quality to help Australian marketers penetrate higher-priced but more selective markets

PHOTO: QAAFI

A better understanding of the functional properties of Australian grains is being pursued to help the local industry access higher-value, niche consumer health markets.

Cereal grains scientist Dr Glen Fox is leading GRDC-supported research into the properties of several grains (including wheat, barley, sorghum, maize and oats) at the Centre for Nutrition and Food Science at the Queensland Alliance for Agriculture and Food Innovation (QAAFI). The hope is for future crop varieties targeting specific health function properties, such as oats with higher beta-glucan levels to help reduce cholesterol. For consumers it means more grains-based foods with enhanced health properties.

Dr Fox says it is important to understand not just the basic components of grain – the proteins and carbohydrates, for instance – but also the quality of those components and how they perform when subjected to processing.

“There can be significant changes in food qualities during processing, and also in what finally ends up in food and in the human gut. It’s really about starting at the human end and working back,” he says.

“We are unravelling some of the hidden components that processors are interested in, and we need to link that to the classification of our grains and to breeding so that either existing varieties can be tweaked or new varieties, better suited to niche markets, developed.

“Our research is targeting high-performance traits that certain buyers will want regardless of price, rather than a bulk commodity with an ‘average’ performance across a range of uses. Markets can already buy millions of tonnes of this, and from anywhere, because it’s just an average quality.”

Some of QAAFI’s research into grain functionality is being done in partnership with the GRDC-supported Australian Export Grains Innovation Centre, based in Perth. QAAFI is an institute of the University of Queensland and is jointly supported by the Queensland Government.

Barley performance

In other grains performance research, Dr Fox is looking to improve the malting performance of barley and to reduce sprouting and visual defects.

Dr Fox says maltsters typically use three or four key specifications in selecting barley for malting prior to brewing, but sometimes the grain does not perform as expected in brewing, despite meeting these specifications.

His research is analysing dozens of other compounds in barley to identify which may contribute to these ‘out of spec’ results in malt and final brewing performance. This would allow maltsters and brewers to retest and troubleshoot – given they may have thousands of tonnes of barley or malt in storage.

He says understanding starch structure is particularly important for cereals such as barley and wheat. The size and structure of starch molecules can look very different as a result of environmental factors, particularly temperature extremes during grain fill. Grain from locations sharing similar weather conditions is more likely to have a similar starch structure than a single variety from a range of locations, which has experienced significantly different weather conditions.

“Measuring total starch does not tell us what the starch looks like and how it will perform in different situations during processing,” Dr Fox says. “And when grains such as barley are 55 per cent starch, or wheat at 65 per cent starch or more, this can really make a difference to the end result.”

The other barley research Dr Fox is conducting aims to determine what causes black point – a black layer of lignin-like compound on the germ of the grain, which does not appear to have any effect on the processing performance of barley in malting or brewing.

“But visually, customers don’t like it. Some customers have a zero tolerance for black point. A whole shipment could be rejected on the basis of one affected kernel,” he says. Another project is identifying resistance to pre-harvest sprouting, which is triggered by rain. This project has already identified some germplasm with improved resistance, which has been provided to barley breeders.

However, a bigger issue for maltsters is partial germination of the grain in storage, which results in dead grain in the final malt product and can represent a significant loss.

“We know what causes pre-harvest sprouting – rain. But the germination in storage is unpredictable; even crops that don’t get rain during harvest can suffer from this. In 100,000 tonnes of barley, if 10,000t doesn’t germinate during malting because it’s already partially germinated, you lose 10 per cent of production.”

He says work to date indicates that storage conditions can exacerbate the problem, including on-farm storage prior to sale of the barley, but further research hopes to identify clear triggers and also barley germplasm that is more resistant to the problem.

The black point and sprouting research is being undertaken in conjunction with Murdoch University’s Professor Chengdao Li in Western Australia, who leads this work. QAAFI carries out the related research in eastern Australia.

This project has been jointly supported by the Department of Agriculture and Fisheries and the University of Queensland, with support from AEGIC and Murdoch University.

More information:

Dr Glen Fox,
07 4639 8830,
g.fox1@uq.edu.au

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GRDC Project Code UMU00047, AEG00006

Region National