Effect of wet ball milling on physicochemical properties and crosslinking reaction performance of corn starch

Corn starch was physically modified with a ball mill in ethanol. The effect of ball-milling treatment on particle morphology, particle size distribution, crystalline structure, and pasting property was examined by means of scanning electron microscopy (SEM), laser diffractometer, X-ray diffraction (XRD), and rapid viscosity analyzer (RVA). In addition, the ball-milling effect on crosslinking performance of corn starch was also investigated. It was observed that the milled starch granules lost surface smoothness at high milling loads (25 and 30 g), while some granules were squashed at low milling loads (15 and 20 g). As milling load decreased from 30 to 15 g, the milled starch showed increase in volume average diameter (D[4,3]) from 13.49 to 15.45 mm. The crystalline structure of starch was partly destroyed by the milling. The pasting temperature and peak viscosity of milled starch decreased with decreasing milling load. The starch samples show improvement in crosslinking process following ball-milling treatment as indicated by increased phosphorus content.