The persistence of heat resisting lectins in foods pose serious health hazards and this has driven studies into finding suitable ways to attenuate their possible risks in foods that contain high levels such as beans. Many of the adverse effects of lectins are attributable to their binding to specific membrane-bound carbohydrates with unique structures. Thus, the aim of this study was to determine the effects of the use of -radiated starches in inactivating lectins in five NULs flours, studied in an extruder serving as a bioreactor. Firstly, radiated starches were prepared using radiation doses from 3 kGy to 42 kGy. Defatted NULs flours were composited at 10% of the radiated starches in respect of the quantities of the native starches present. The composites were agitated in an extruder which operated within intrinsic temperature changes ranging from 2°C to 12°C. Residual lectins from the extrudates were quantified by ELISA analysis. Mamdani type fuzzy logic inference system was used to model the two input variables to predict the optimal lectin inactivation at 100% accuracy. While lectins from Canavalia sp. recorded 83.1% inactivation, lectins from Vigna sp. rather potentiated up to 44%. Thus, -radiated starches, incorporation into NULs flours during low temperature extrusion treatment, inactivated NULs lectins at varying degrees which were adequately predicted by the model.