Quantifying cyanogenic glycoside production in the acrospires of germinating barley grains

Ethyl carbamate is an undesirable trace component in distilled beverages and its content in Scotch whisky is largely determined by the cyanogenic pre-cursor, epi-heterodendrin (EPH) from malted barley. A rapid colorimetric procedure can identify cultivars that do not produce EPH and attempts were made to quantify this test, to determine differing levels of production. Using a given fresh weight of acrospire tissue from germinated grain, it was possible to distinguish between genotypes but differences between replicates were substantial. Acrospire length was not a reliable indicator of EPH production and genotypes differed not only in the quantity of EPH produced but in the rate and pattern of production.