Using Electrolyzed Oxidizing Water in Controlling Bacteria for Prolonging Storage-life of Organic Vegetables

Abstract

The purpose of this study was to examine the effects of electrolyzed oxidizing water (EO water) on reduction of rot disease in organic vegetables. EO water was produced in various concentrations of NaCl at 0.00625, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.3, 0.4 and 0.5 percent. Then the free chlorine concentrations and pH values were measured in the range of 0.40-137.00 ppm and 3.65-4.11, respectively. While the electrolyte conductivity (EC) showed in the range of 0.49-6.23 mS/cm. Erwinia carotovora, bacterial pathogens of soft rot disease were isolated from Chinese cabbage and were used for inhibitory effect trials of EO water. Bacterial suspension cells were soaked for 1 and 5 min into each concentration of EO water. After incubated on NA medium for 24-48 hrs., results showed that the bacterial growth was completely inhibited except the trial of EO water at concentration of 0.00625 percent which was found very few colonies grew up. In addition, magnification observed on the bacterial cell size, revealed that those the EO treated trials showed smaller size than in the control (distilled water) treatment, except in the concentrations of 0.00625 and 0.0125 percent. Applications of various concentrations of EO water for reduction of soft rot disease were done on organic vegetables (Chinese cabbage and Cos lettuce) and the results showed that the 0.3 percent EO treatment was the best to reduce soft rot incident. Then, soft rot inhibitory effect of EO water at 0.3 percent was compared to other disinfectants; Ozone water (0.02 percent), potassium permanganate (0.05 g/l), sodium bicarbonate (2.5 g/l) and chlorinated water (0.02 percent). The results revealed that EO water could reduce soft rot disease and prolong shelf-life of organic vegetables (Chinese cabbage and Cos lettuce) better than other disinfectant solutions.