More on grain quality

UNIVERSITY OF Adelaide researcher Kolumbina Mrva is concentrating on another aspect of grain quality - a condition in grain known as late maturity alpha amylase or LMA.

The release of the enzyme amylase is triggered by cool temperatures at the middle stage of grain filling in varieties that carry this genetic defect. LMA causes excessive starch breakdown during processing, making end products unacceptably 'sticky'.

Dr Mrva has identified a number of advanced breeding lines and varieties prone to LMA, has pinpointed the original sources of this defect, and is working closely with Australian breeders to overcome the- problem - important steps given that some grain buyers are suggesting that one requirement for the release of any new wheat variety should be a demonstrated absence of LMA.

Varieties like KennedyPBR logo, Currawong, Triller and Lillimur, and a number from WA, are prone to LMA. With CSIRO, Dr Mrva has also developed a test for LMA that can be used to distinguish LMA from pre-harvest sprouting (both result in high alpha amylase activity and hence serious grain quality deterioration), and which is also part of a screening test to identify the genes responsible.

Another aspect of the work is collaboration with Dr Peter Williamson at the Queensland Department of Primary Industries in producing varieties more resistant to black point. Black point doesn't damage the starch or protein in the flour but the black seed coat breaks into fine particles during milling, resulting in specks in the flour. It is particularly important to avoid this contamination in Asian noodles or durum products.

Program 1 Contact: Dr Kolumbina Mrva 08 8303 4455

Region North