Alkaline (AIEW) and acidic electrolyzed water (AcEW) were prepared by the electrolysis of a dilute sodium nitrate solution. The efficacy of AIEW (pH 11.5) In removing the gelatin deposited on stainless steel particles was compared with that of warm deionized water (DIW
pH 5.7) at various temperatures of 20 to 80°C. The efficiency of the DIW cleaning increased with Increasing temperatures from 20 to 70°C, whereas it decreased to some extent at 80°C. On the other hand, the efficiency of AIEW cleaning increased with increasing temperatures up to 50°C, above which it decreased gradually. AIEW cleaning was shown to be by far more effective in removing gelatin than warm DIW cleaning, and its optimum temperature was 50°C. AcEW cleaning removed calcium hydrogenphosphate deposited on stainless steel particles, depending on the solution pH, and resulted in the modification of the surface charge of stainless steel particles, due to the oxidizing action of nitrate in AcEW.