The (1-3,1-4)-ß-Glucanases in Malting Barley: Enzyme Survival and Genetic and Environmental Effects
J.E. Georg-Kraemer 1,6, E. Caierão 2, E. Minella 3,
J.F. Barbosa-Neto 5 and S.S. Cavalli 1,4,6
1 Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
2 AmBev, Companhia Brasileira de Bebidas, Porto Alegre, RS, Brazil.
3 Empresa Brasileira de Pesquisa Agropecuária, Embrapa-Trigo, Passo Fundo, RS, Brazil.
4 Laboratório de Diagnóstico Genético-Molecular da Biodiversidade, Programa de Pós-Graduação em Diagnóstico Genético-Molecular, Universidade Luterana do Brasil, Rua Miguel Tostes, no. 101, 92420-280, Canoas, RS, Brazil.
5 Departamento de Plantas de Lavoura, Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
6 Corresponding authors. E-mail: janaina.kraemer@terra.com.br and suzana.cavalli@terra.com.br
J. Inst. Brew. 110(4), 303-308, 2004 | VIEW ARTICLE
ABSTRACT
Eighteen barley genotypes used in Brazilian malting barley breeding programs were characterized in relation to (1-3,1-4)-ß- glucanase activity in green and kilned malt. They were tested to determine the loss of enzyme activity during kilning in the malting process and the environmental effects on enzyme activity were measured. The genotypes analyzed showed great variation regarding the enzyme activity in both kinds of malt, in a range from 531.94 to 934.31 U/kg in green malt, and from 187.02 to 518.40 U/kg in dry malt. The mean enzyme activity loss during kilning was close to 60%, very similar to the results obtained in other studies. The loss among genotypes varied from 8.04% to 71.54%. The enzyme activity varied significantly under the different environments tested, showing existence of environmental effects on the genotypes analyzed. Embrapa 127 was the genotype that exhibited the highest enzyme activity in finished malt although it had shown a low activity in green malt, reflecting a negligible loss of activity during kilning. The data indicate promising results to malting barley breeding due to the wide variability exhibited by genotypes as to enzyme activity and levels of isoenzyme with high thermostability.
Key words:
Barley, (1-3,1-4)-ß-glucanases, environmental, enzyme
activity, kilning, malting.
Publication no. G-2004-1230-240 ©2004 The Institute & Guild of Brewing