Science taps lupin potential

Photo of lupins growing in wide rows

To transform lupins into a more significant crop across Australia, the Grdc supports many programs looking at yield, disease and weed control. susan Hall looks at the current efforts to make lupins a premium product

A major push is being made to lift lupin yields to make this popular legume in Western Australia more attractive to growers elsewhere in Australia. More than 80 per cent of the world"s lupins are grown in WA, where it is a valuable nitrogen-fixing rotation crop. However, more needs to be done to lift yields and quality to bring lupins into the cropping mainstream.

Mark Sweetingham, grain legume program manager with the WA Department of Agriculture, says current projects are looking at end-user requirements, the identification of unique or superior attributes and the development of better varieties and agronomic packages to lift lupins" appeal to growers.

"Lupins are a particularly important crop in WA, where our strong research base is complemented in the paddock by very innovative growers," says Dr Sweetingham. "However, to lift production and capitalise on new market opportunities we have to focus on yield, rather than just hectares planted."

He says all farming systems can benefit from the disease break for cereals and oilseeds, and lupins provide mixed-cropping and livestock properties with an on-farm feed source.

In WA, lupins also fix about $100 million worth of nitrogen in the soil annually.

However, annual ryegrass and wild radish can be a problem for lupin crops. "To overcome them, researchers and growers will need to think smarter about herbicides and weed management options, using older and newer herbicides and rethinking the most efficient way to use triazines.

"Inter- and intra-row spraying, using a shielded or hooded sprayer, are emerging as profitable options for growers using tramline systems."

Despite Australia boasting the world"s largest breeding program and genetic resource banks, there remain some significant lupin breeding challenges.

Although valuable metribuzin tolerance was recently bred into the cultivar MandelupPBR, this process will be made more efficient using a DNA marker, recently developed by researchers at the Centre for Legumes in Mediterranean Agriculture (CLIMA).

Disease threats to be addressed in the breeding program include anthracnose, phomopsis, brown spot, bean yellow mosaic virus and cucumber mosaic virus.

"Anthracnose, the most critical disease of lupins, presents a particular challenge," Dr Sweetingham says. "Currently, two different resistance genes are available to breeders, one in TanjilPBR and the other in MandelupPBR. Each confers strong resistance in stems but very little in flower and pod tissue, and breeders need to overcome this."

He says that an improved anthracnose management package, involving resistance, agronomics and chemical solutions, would be worth about $30 million a year in increased production to WA growers alone.

At a recent CLIMA seminar, Dr Sweetingham acknowledged that with lupins a relatively small crop, some industry observers understandably question the level of funding for lupin breeding. But he noted that lupins have outstanding food ingredient potential, particularly for processed protein and fibre components, and the protein fraction also has potential as premium stockfeed ingredients.

"The underlying demand for lupin as a feed protein source can only increase, due to the ban on meat meal in Europe and increasing meat consumption in Asia, as well as a push for more options in a market increasingly dominated by genetically modified (GM) soybean meal," Dr Sweetingham says. "Lupin protein is also being thoroughly investigated as a replacement for fish meal in the aquaculture industry, where its higher protein digestibility, lower phosphorus effluent and better oil absorption in extruded pellets give it a competitive advantage over other plant protein sources.

"In terms of human food ingredients, lupin protein and fibre is valued for its functional and nutritional benefits.

"The health benefits of lupins are increasingly recognised thanks to a unique combination of high protein and fibre, with low oil and no starch, meaning lupins boast a low glycaemic index compared to other grains.

"Australian lupins are clean and contaminant free and commercial interest in lupins has been sparked in part due to their non-GM status," he says.

Researchers are investigating a minor protein component in lupins which shows promise as a viable egg white replacement, with better foaming properties, reduced salmonella risk and a premium price in the order of $7.50 a kilogram. "Best of all, in a comparative sense, soybean does not contain this particular protein."

Dr Sweetingham believes the possible uses for the lupin protein are almost endless - from dairy substitutes such as milk, yoghurt and ice cream through to meat extenders and surimi (fish paste).

Also, lupin milk made in the Department of Agriculture laboratories has shown a high sensory appeal in comparative taste tests against similar commercial products.

GRDC-supported research has been working on isolating and developing lupin protein products, including lupin concentrates and isolates of varying protein concentrations.

"Lupin flour, produced by de-hulling the grain and grinding the kernels, makes an excellent additive in bakery products. At correct inclusion rates, the important end-product colour is exceptional," Dr Sweetingham says.

Further GRDC-supported research at Deakin University in Victoria has found lupin fibre has significant dietary qualities - more filling and satisfying than other fibres, while lowering cholesterol and suppressing appetite. This superior fibre is contained in the lupin kernel, which comprises 75 per cent of the lupin, with the hull making up the balance.

GRDC is also supporting research into reducing hull thickness, which will make lupins easier to process and increase the proportion of the more valuable kernel.

It is expected that reducing hull thickness to 18 per cent from the current 25 per cent should increase grain value by about $13 a tonne on current prices and divert the carbon into increased kernel protein, oil or pectin.

Other lupin species such as yellow lupins show potential in their higher protein content and improved amino acid profile.

"To fully realise the potential of lupins, we have to focus on profitability throughout the value-chain and coordinate improved genetics, on-farm production technology and product development," says Dr Sweetingham.

GRDC Research Code DAW00105
For more information: Dr Mark Sweetingham, 08 9368 3298, sweetingham@agric.wa.gov.au

PBR Varieties displaying this symbol beside them are protected under the Plant Breeders Rights Act 1994.

[Photo: Lupins grown in wide rows. The legume fixes about $100 million worth of nitrogen in the soil each year in WA alone.]