To achieve this, two different assays were applied to measure selected samples: the azocasein assay described above (determining absorption differences) and the casein/o-phthaldialdehyde assay described by Baur et al. (2015b) (determining enzyme activities). The results for the selected samples obtained with the two assays were correlated. From the correlation between absorption difference in ΔA h−1 mL−1 and enzyme activity in pkat mL−1, the enzyme activity was calculated for all the samples.