UV–vis measurements proved that the new enzymatic composites
also exhibit important biocatalytic activity which increases at higher
temperatures. Far more, this immobilization act of Tyr led to an increase
of the thermal stability relative to the free enzyme. The reaction rate of
the immobilized enzyme decreases in the first 10 min and it increases
with the increase in substrate (PC) concentration. Plus, the presence of
PVA in the membrane seems to have a positive effect upon the enzyme
microenvironment near the membrane surface.