β-amylase extracted from Pergularia tomentosa was characterized by 1.98 U/mg protein of enzyme activity and a molecular weight of 24 KDa. Enzyme was immobilized onto a matrix of titanium dioxide-based materials incorporated to cellulose acetate butyrate and copolymer of acrylonitrile-acrylamide, and its specific activity was 0.34 U/mg protein. A newly kinetic mechanism of a plant enzyme was studied by the means of the variation of the conversion degree α in function of the temperature increase. Modified Prout-Tompkins topochemical equation described the kinetic process of the free and the immobilized β-amylase. The specific nature of the process was determined by plans and enzyme activity. The current rate was responsible for the behavior of active centers. The apparent rate constant and the power factor were depending on the temperature. The topochemical process of the free β-amylase was explained by the influence of the current rate decrease with 2.8% at 60 °C by the pre-exponential factor and the inhibition of the enzyme due to the obtained product. With immobilization, the decrease of the current rate of the process, 7.91% at 70 °C, was due to the change in the number and the accessibility of active centers on the surface.