Barley: blue aleurone

Page last updated: Tuesday, 20 September 2016 - 11:15am

Please note: This content may be out of date and is currently under review.

A blue colouring in the aleurone layer of barley grain (the layer immediately below the husk) may be present in some varieties. While it is genetically controlled, its expression is under environmental influence. Australia is committed to supplying customers of malt, food and feed grade barley with grain that has a white aleurone.

Appearance

Barley with a blue aleurone layer has grain with a blue tinge that is visible through the husk (as in figure 1).

Two barley grains give a side by side comparison of the extent of blue coloring in the aleurone layer where the first has a blue tinge that is only seen when the husk is removed, the second is bright enough to show clearly through the husk
Figure 1. Comparison of blue aleurone colouring in barley grain.

Cause

Some barley varieties are bred with a blue aleurone layer below the husk which give the blue tinge, its expression is also under environmental influence which means that the conditions under which the crop is grown will determine the prominence of the blue aleurone within the kernel.

Receivals

Blue kernel barley has a poor visual appearance, with white aleurone barleys being preferred by buyers of Australian barley. Receival standards in Western Australia have a nil tolerance for blue aleurone grain in malt barley deliveries and a maximum allowance of 1 in 100 grains in feed barley deliveries.

Henley

A recently accredited malting barley variety, Henley, has a noted blue aleurone. Although this was not observed during malting and brewing trials it has now become apparent in commercial deliveries of the variety. As there is a national committment to supply customers of Australian malt, food and feed grade barley with white aleurone grain, the presence of the blue aleurone in Henley means there is a risk that it will not consistently meet required standards.

As a result, Henley is being withdrawn from the marketplace by Heritage Seeds (the distributor of Henley).

Growers who delivered Henley in 2013 should have received a letter from the Grains Industry Association of Western Australia (GIWA), if you have not received this it is recommended you contact GIWA or Heritage Seeds.

For more information see: