The Fructan Assay Kit (K-FRUC) is recommended for the measurement of fructans that include levan.
The K-FRUC kit has been updated to include endo-levanase (AOAC Method 2018.07) and thus is applicable to the measurement of all types of fructan including levans in grasses. However, endo-levanase has not been included in the K-FRUCHK kit. The reason for this is that fructans, including levans in grasses are non-reducing, so the best method to use is K-FRUC with borohydride removal of background sugars.