Relationship between hordein proteins and malt quality in barley cultivars grown in Croatia

The hordein proteins of ten barley (Hordeum vidgare L.) cultivars grown in region of eastern Croatia were studied for their contribution to the malting quality, particularly relating hordein influence on malt extract yield. The analysis of hordein proteins was carried out by reversed-phase high-performance liquid chromatography (RP-HPLC). The micromalting of investigated barley cultivars and malt analyses were done according to the EBC official methods. The quantitative analysis of hordein proteins has showed that 13-hordein was major component, followed by C- and D-hordeins. Among investigated cultivars the malt extract yield varied from 76.8% (cv. Angora) to 82.6% (cv. Scarlett). Spring barleys had on the average higher malt extract yield in contrast to winter barleys. The significant negative correlation between the total hordem content and malt extract yield was found. Among hordein fractions the 13-hordein and D-hordein significantly contributed to lower malt extract yield. RP-HPLC analysis of malt hordeins revealed that the amount of hordein degraded during malting significantly correlated with Kolbach index.