Comparative kinetic evaluation of native and gelatinised starch hydrolysis by α-amylases

Native starch-degrading α-amylases offer opportunities for more sustainable starch-processing strategies. While individual native starch-degrading α-amylases have been studied, systematic quantitative and comparative analyses are scarce and often limited to single-time-point measurements. Here, we present a rapid comparative approach to evaluate the hydrolytic performance of various α-amylases on native and gelatinised starch across six time points. Maximum native starch hydrolysis levels after 24 h of incubation at 40°C and pH 5.0 ranged from 4 % to 47 %, while native starch binding capacities toward wheat starch varied from 12 to 86 %. Native starch binding capacity correlated positively with both maximum native starch hydrolysis (Pearson's r = 0.57, p < 0.05) and the initial native starch hydrolysis rate (Pearson's r = 0.68, p < 0.01), indicating that it is a valuable preliminary parameter for assessing native starch hydrolysis potential. Hydrolysis profiling combined with native starch binding capacity assessment provides a rapid and effective framework for identifying promising native starch-degrading α-amylases.