Determination of ergosterol levels in barley and malt varieties in the Czech Republic via HPLC.

Ergosterol is considered to be a suitable indicator of mold infestation in barley and malt. In this study ergosterol levels in different varieties of barley and malt produced in the Czech Republic were determined. A modified high-performance liquid chromatography (HPLC) method was statistically processed, validated (Effivalidation program), and applied to 124 samples of barley and malt. Ergosterol was isolated by extraction and saponification, and the quantification was performed using HPLC with diode array detection. The content of ergosterol ranged between the limit of detection (LOD) and 36.3 mg/kg in barley and between the LOD and 131.1 mg/kg in malt. Ergosterol is presumably connected with metabolites generated when barley grain is attacked by pathogens, and such barley often shows a high overfoaming (gushing) value. However, it was found that the content of ergosterol does not correlate with the degree of beer gushing.