Protein oxidation is defined as the covalent modification of a protein induced either directly by reactive oxygen species or indirectly by reactions with secondary by-products of oxidative stress.
Oxidative modification of proteins can be induced experimentally by a wide array of pre-oxidant agents and occur in vivo during aging and in certain disease conditions.
The oxidation degree in this study was determined by the protein carbonyl content.
The protein carbonyl content of the control sample was zero.
After treatment (25 kV/cm, 800 ls), there was no increase in protein carbonyl content.
Previous studies detected that hydrogen radicals are generated from the hydrogen ion of water in a phosphate buffer and oleic acid emulsion (Zhao et al., 2011; Zhang et al., 2011c).
The difference effects between protein solution, phosphate buffer and oleic emulsion systems could be due to solution composition and conditions of processing.