Reduction of Pesticide Residues on Fresh Vegetables with Electrolyzed Water Treatment

Abstract

Degradation of the 3 pesticides (acephate, omethoate, and dimethyl dichloroviny phosphate [DDVP]) by electrolyzed water was investigated. These pesticides were commonly used as broad-spectrum insecticides in pest control and high-residual levels had been detected in vegetables. Our research showed that the electrolyzed oxidizing (EO) water (pH 2.3, available chlorine concentration:70 ppm, oxidation-reduction potential [ORP]: 1170 mV) and the electrolyzed reducing (ER) water (pH 11.6, ORP: -860 mV) can reduce the pesticide residues effectively. Pesticide residues on fresh spinach after 30 min of immersion in electrolyzed water reduced acephate by 74% (EO) and 86% (ER), omethoate by 62% (EO) and 75% (ER), DDVP by 59% (EO) and 46% (ER), respectively. The efficacy of using EO water or ER water was found to be better than that of using tap water or detergent (both were reduced by more than 25%). Besides spinach, the cabbage and leek polluted by DDVP were also investigated and the degradation efficacies were similar to the spinach. Moreover, we found that the residual level of pesticide residue decreased with prolonged immersion time. Using EO or ER water to wash the vegetables did not affect the contents of Vitamin C, which inferred that the applications of EO or ER water to wash the vegetables would not result in loss of nutrition.

Removal of six pesticide residues in cowpea with alkaline electrolysed water

“…As shown in Table S1, the reduction rate of pesticide residues by AlEW solution was obviously larger than tap water, 5% sodium chloride, 5% sodium carbonate and 5% acetic acid solution for each pesticide at the same washing time, and the reduction rate by AlEW solution was as high as 85% while the highest removal rate of pesticide residues by tap water or other washing solutions is only 55%. This indicated that the efficacy of washing treatment by AlEW solutions was apparently superior to washing with tap water, 5% sodium chloride, 5% sodium carbonate and 5% acetic acid solution in eliminating pesticide residues which was in accordance with the results obtained by Hao et al In addition, as presented in Fig. , the reduction rate presented a gradual increase with the increase of pH for AlEW solutions, and the reduction rate was the highest when the pH reached to 12.2 which was in line with the previous study by Fan et al To some extent, the reduction rate was related to the pH of the washing solutions.…”

“…The alkaline electrolysed water (AlEW) is of high pH value and low ORP which is a potential mean to remove pesticide residues from fresh vegetables and fruits …”

“…The EO water is generated at the anode side with low pH value (2.3–2.7), high oxidation–reduction potential (ORP, >1000 mV) and hypochlorous acid which has been determined to have a strong bactericidal effect on most known pathogenic bacteria and used as an alternative to conventional fungicides for controlling plant diseases . The electrolysed reducing (ER) water is generated at the cathode side with high pH value and low ORP, which has limited application in the food industry due to the lack of strong antibacterial activity . However, Lin et al found that the alkaline electrolysed water reduced 98% of methamidophos in spinach.…”

Controlled release of methylene blue from glutaraldehyde‐modified gelatin

“…Controlled release technique has been widely used for food applications such as developing functional microcapsules to control the release of flavoring ingredients at a desired time or with a specific rate and protecting unstable food ingredients under processing, storage, and digestion (Hao et al, ; Liu et al, ; Madene, Jacquot, Scher, & Desobry, ). Yeo, Bellas, Firestone, Langer, and Kohane () encapsulated flavor oil in coacervate microparticles to retain the flavor of frozen baked foods during heating process.…”

Degradation of four organophosphorous pesticides catalyzed by chitosan-metal coordination complexes

“…There are three main routes for OP degradation in the environment: physical degradation (Hao et al 2011;Golash and Gogate 2012;Rao et al 2012), chemical degradation (Bai et al 2010;Ling et al 2011;Qiang et al 2013), and microbial degradation (Cáceresa et al 2007;Ruoss et al 2011;Sasikala et al 2012), of which chemical degradation has received the greatest attention (Tang et al 1998). Chemical degradation includes hydrolysis and oxidation reactions; the former is considered to be the most important.…”