Malting Behaviour of Barleys Grown in Canada and Spain as Related to Hordein and Enzyme Content

J.-L. Molina-Cano ^1,3, J.P. Polo1, I. Romagosa ¹ and A.W. MacGregor ^2
1Centre UdL-IRTA, Av. Rovira Roure 177, 25198 Lleida, Spain.
²Grain Research Laboratory, Winnipeg, Manitoba, Canada.
³Corresponding author. E-mail: joseluis.molina@irta.es

J. Inst. Brew. 110(1), 34–42, 2004  |   VIEW ARTICLE

ABSTRACT
To continue our effort to analyse the genetic (varietal) and environmental (sites and years) effects on malting quality of barley, we have field-tested four barley varieties, two- and six-rowed, European and North American, in Spain and Canada in 1998 and 1999. The Spanish trials were autumn-sown whereas the Canadian ones were spring-sown. Barley grain was analysed for total protein and hordein contents and micromalted. Canadian-grown barleys had significantly lower contents of grain protein and allthree hordein fractions than the Spanish ones. They also had lower malt respiratory losses, wort β-glucan and viscosity but lower fine- and coarse-ground malt extract yield, friability, free amino nitrogen, Kolbach index, α-amylase and diastatic power. In other words, the Canadian-grown barleys, despite showing lower protein and hordein contents, produced malt of inferior quality than their Spanish counterparts, which, overall, produced higher quantities of degrading enzymes (amylolytic, proteolytic and cytolytic) during germination, thus being able to attain higher extract yield levels.

Key words:
Barley, environment, hordein, malting quality, protein.

Publication no. G-2004-0309-211 ^©2004 The Institute & Guild of Brewing