The use of \(\alpha\) -amylase in the food, feed, and industrial sectors is constantly increasing, especially in the context of sustainable development. Modeling starch hydrolysis by commercial \(\alpha\) -amylase with enzyme deactivation was performed for initial concentration of \({20\%}\) , \({30\%}\) and \({40\%}\) at 333 K. However, earlier in this study, need to determine the parameters of the starch hydrolysis process using commercial \(\alpha\) -amylase from Bacillus spp. The analysis focused on determining the deactivation energy \({E_{{\text{d}}}}\) in starch hydrolysis while simultaneously deactivating commercial \(\alpha\) -amylases from Bacillus subtillis and Bacillus licheniformis. The mathematical model applied assumes that the changes in starch concentrations and the deactivation of commercially bacterial \(\alpha\) -amylase are first-order reactions with respect to enzyme concentration. The calculated activation energies \({E_{{\text{a}}}}\) ranged from \({22.08 \pm 6.96}\) kJ \(\text {mol}^{-1}\) to \({70.35 \pm 15.24}\) kJ \(\text {mol}^{-1}\) , and the deactivation energies \({E_{{\text{d}}}}\) ranged from \({21.30 \pm 1.05}\) kJ \(\text {mol}^{-1}\) to \({163.66 \pm 6.57}\) kJ \(\text {mol}^{-1}\) . The results obtained in this study were used to model the conversion of starch hydrolysis by commercial \(\alpha\) -amylase from Bacillus spp. Additionally, the obtained \({E_{\text{a}}}\) and \({E_{\text{d}}}\) values from the activity versus temperature were compared to the \({E_{{{\text{a}}}}}\) and \({E_{{{\text{d}}}}}\) values obtained using the Arrhenius methods. The obtained activation energies \({E_{{{\text{a}}}}}\) and deactivation energies \({E_{{{\text{d}}}}}\) allow to modeling hydrolysis of starch by \(\alpha\) -amylase from Bacillus spp. Presented modeling of starch hydrolysis with commercial \(\alpha\) -amylase deactivation is essential to optimize the use of commercial \(\alpha\) -amylase, improve process efficiency and minimize costs in large-scale applications.
