Electrochemical Monitoring and Kinetic Modeling of the Enzymatic Hydrolysis of Tapioca Starch

In this study, an electrochemical method was used for real-time monitoring of the hydrolysis of native, acetylated, modified, and thermally treated tapioca starch using an amperometric technique. The measurements were performed with low-cost screen-printed electrodes at an optimal potential of 0.1 V and a scan rate of 50 mVs-¹. The tapioca starches were hydrolyzed by alpha amylase enzyme at reaction times ranging from 0 to 60 min, temperatures of 40°C and 50°C, and pH values of 5.0 and 7.0, respectively. This approach was found to yield glucose concentrations comparable with those obtained by the standard chemical method (spectrophotometry measurement) with no statistically significant difference (p< 0.05) in most of the studied conditions. The kinetics modeling of the enzymatic hydrolysis that yielded glucose revealed that both the first-order kinetic model and Chapman-Richard’s function model had good predictions of the hydrolysis process. Although both models successfully captured the nonlinear complexities involved in the electro oxidation process of glucose at the different temperatures and pH values, the Chapman-Richard function model demonstrated a better prediction than the first-order kinetic model. The findings revealed that applying electrochemical sensing with kinetic models has the potential to help develop rapid and inexpensive methods for in process monitoring of the hydrolysis of starch-based product in the food industry.