The first ESR observation of radical species generated under pulsed electric fields processing

Abstract

Electron spin resonance (ESR) spectroscopy was used to investigate the generation of free radicals under pulsed electric field (PEF) processing. Spin trapping studies, using 5,5-dimethyl-1-pyrroline N-oxide (DMPO), showed the generation of hydrogen radicals in phosphate buffer and oleic acid emulsion. The concentration of hydrogen peroxide in phosphate buffer after PEF treatment was determined by spectrofluorometric method. Electric field strength has a significant effect on the concentration of H2O2 (p < 0.05). In PEF-treated samples with electric field strength of 30 kV/cm and 35 kV/cm, trace concentrations of H2O2 (0.177 × 10−6 and 2.035 × 10−6 mol/L, respectively) were detected.