Pathogenic Metabolites in Barley Caryopses and Their Effect on Quality of Malting Barley and Malt

In 2008-2010 69 samples of hulled and hulless barley varieties and lines and malt made from them were analyzed. Activity of enzymes involved in the plant defense response to the pathogenic attack - chitinase and 1,3-beta-glucanase was monitored. In addition, galactomanan polysaccharide present in the cell walls of filamentous micromycetes was studied using the agglutination EPS test. beta-glucan content was studied in non-malted barley caryopses and in wort. Simultaneously, gushing potential of barley and malt and content of dimethyl sulfide precursors in malt were studied. 1,3-beta-glucanase activity in malt is mostly a result of the germination process and therefore it is not a result of a pathogenic assault. Most likely, contamination of caryopsis does not principally affect beta-glucan content. On the contrary, level of gushing and PDMS content in malt are markedly associated with the contamination of caryopses with filamentous micromycetes.