1 U er den mængde enzym, der frigiver 1 mikromol reducerende sukker (glucoseækvivalenter) fra byg-beta-glucan pr. minut ved pH 5,0 og 30 °C.
1 U is the amount of enzyme which liberates 1 micromole of reducing sugars (glucose equivalents) from barley beta-glucan per minute at pH 5,0 and 30 °C.