Effects of pulsed electric fields (PEF) treatment on the properties of corn starch

Corn starch-water suspensions (8.0%) were processed in the pulsed electric fields (PEF) with different electric field strength up to 50 kV cm(-1). Effects of pulsed electric fields PEF treatment on the properties of corn starch were systematically studied by differential scanning calorimetry (DSC), laser scattering, X-ray diffractometry (XRD), scanning electron microscopy (SEM) and the Brabender rheological method. The results showed that gelatinization temperatures and enthalpy decreased with the increase of electric field strength. After the PEF treatment at 50 kV cm(-1). starch lost granule shape, and the crystallinity degree were decreased significantly. Meanwhile, the peak, breakdown and final viscosity of treated starch were decreased with increasing electric field strength. In conclusion, corn starch was sensitive to be gelatinized due to the rearrangement and destruction of starch molecular structure during PEF treatment. It provides a useful method to modify properties of starch and get a desired production in food application. (C) 2009 Elsevier Ltd. All rights reserved.