Functional, physicochemical properties and structure of cross-linked oxidized maize starch

Cross-linked, oxidized and cross-linked oxidized maize starches were prepared with hydrogen peroxide and sodium trimetaphosphate (STMP), respectively. The physicochemical properties, determined by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), confirmed that the native maize starch was successfully modified. The functional properties (solubility, light transmittance, retrogradation rate and freeze–thaw stability) of native and modified starches demonstrated that cross-linked starch displayed the best freeze–thaw stability. The light transmittance and retrogradation properties of cross-linked oxidized starch were highly improved compared to the native starch. This work suggested that both cross-linking and oxidation firstly happened in amorphous regions of the starch, and a possible structure of cross-linked oxidized maize starch and reaction mechanisms were hypothesized.