Hot Water Extracts in a Mutant Derived from the Barley Cultivar Troubadour

The mutant barley genotype TR49 and the cultivar from which it was derived, Troubadour, were grown at four sites throughout Spain in 1989 and 1990. Significant differences due to genotype and environment were detected for a range of malting quality parameters in 1990. Hot water extract was correlated with a number of factors which contribute to the structure of the endosperm or ease of its modification, such as β-glucan content, malt protein and Kolbach index. The levels of α-amylase and β-glucanase, although significantly different between the genotypes, did not give resultant differences in extract. The higher extract of TR49 over Troubadour is most likely to be due to differences in the structure and composition of the endosperm walls which facilitate modification.