The purified enzyme acted optimally at pH 5.5. Further increase
in pH resulted in a decline in enzyme activity. The peak specific
activity of the ginger protease at pH 5.5 was in agreement with
the pH optima of other plant cysteine proteases
All commercially available rennets exhibit
a curvi-linear increase in relative milk clotting activity as pH
drops from pH 7 towards pH 4–5