Abstract: In order to investigate the effect of mechanical force during high pressure homogenization on the chemical reactivity of starch, we prepare cationic starch by the wet method from corn starch subjected to 1, 5 and 7 high pressure homogenization cycles (three stages of mechanical action). The structure and properties of cationic starch were examined by scanning electron microscopy, confocal laser scanning microscopy, polarizing microscopy, X-ray diffraction, rapid visco-analyser and differential scanning calorimetry. The results indicated that high pressure homogenization pretreatment destroyed the crystal structure and improved the chemical reaction activity of starch. This phenomenon was the most pronounced at the stage of aggregation and the peak viscosity, light transmittance and chemical reaction activity of cationic starch prepared at this stage were the highest. In addition, the degree of substitution and reaction efficiency were increased by 43.80% and 43.86%, respectively.

Key words: high pressure homogenization, cationic starch, activation, property, structure