Abstract:Wheat flour was modified by acid and heat-moisture treatment in thermal water kettle.Polarization microscope, scanning electron micrograph, differential scanning calorimetry (DSC) instrument, Brabender viscosity instrument, X-ray diffraction (XRD), infrared spectrometer were used to study the properties enzymatic kinetics of wheat flour before and after the treatment. It was found that, after modification, the protein content was reduced and part of starch granules had shallow crack. Polarization cross was blurring. DSC showed endothermic peak moved backward and absorption enthalpy (ΔH) decreased 2.976 J/g. Brabender viscosity curve indicated that pasting temperature increased from 82.6 ℃ to 87 ℃ and viscosity decreased from 82 BU to 63 BU. XRD showed crystalline structure of starch increased 3.8%. Under in vitro digestion conditions, α-Amylase hydrolyzation of treatment product followed Michaelis-Menten, and enzymatic kinetic equation of product with α-Amylase was obtained as V=0.161[S]/(1.093+[S]). Compared with that without modification, Michealis constant (Km) and maximum rate (Vm) decreased.
