MOŽNOSTI HODNOCENÍ TVRDOSTI ZRNA JEČMENE PŘÍSTROJEM DO-CORDER, JAKO PARAMETRU SLADOVÉ KVALITY

Abstract

There is a need for fast, cheap and sufficient accurate methods for prediction of barley grain quality. The determination of Brabender hardness seems to be promising. The aim of this work was to compare three different methods for evaluation of graphic output from Brabender farinograph and subsequently select the most optimal method for routine laboratory work. 108 samples (twelve cultivars from three localities and three years) were analyzed for grain hardness. Simultaneously selected parameters of grain and malt were determined. The correlations among methods for evaluation were estimated as well as among selected technological traits of barley grain and malt.Grain hardness expressed by area under curve (counted by specific weight of paper ´A´ and measured by planimetr ´B´) showed tendencies to distinguish the varieties by their malting quality. The same trend was not observed for the method C (hardness expressed by maximum value of peak). Nearly perfect positive correlation (0.99***) was found between the results of method A and method B. Medium correlation was found between values obtained by method A and method C (0.58***).Significant correlations were established between values obtained by method A and extract (−0.63***), mash method according to Hartong and Kretschmer (−0.61***), the Kolbach index (−0.70***), friability (−0.71***), β-glucans in wort (0.76***), partly unmodified grains (0.71***), and non-starch polysaccharides content (in total β-glucans and pentosans) (0.67***). Hardness values obtained by method C were related to partly unmodified grains (0.52**), β-glucans in grain (0.61**), and non-starch polysaccharides content (in total β-glucans and pentosans) (0.56**). The most appropriate evaluation method was selected on the base of results of Tukey test as well as the level of correlation among the hardness level and selected quality parameters.