Effect of dielectric barrier discharge plasma on the degradation of malathion and chlorpyrifos on lettuce

Abstract

BACKGROUND: Pesticides have been widely used to control pests on agricultural products in China, and large amounts of pesticide residues have caused a serious threat to human health. Thus, developing a high-efficiency pesticide degradation method for fresh vegetables represents a great challenge. The present study investigated the effects of dielectric barrier discharge (DBD) plasma on the degradation of malathion and chlorpyrifos in aqueous solutions and on lettuces. RESULTS: DBD treatment significantly degraded malathion and chlorpyrifos in water and on lettuce. After cold plasma treatment at 80 kV for 180 s, the degradation efficiency of malathion (0.5 ∼g mL −1) and chlorpyrifos (1.0 ∼g mL −1) in aqueous solutions reached 64.6% and 62.7%, respectively. The degradation intermediates were explored by HPLC-mass spectrometry and the DBD plasma degradation pathways of malathion and chlorpyrifos were proposed. There was no significant damage to the quality of lettuces, including color and chlorophyll content, after plasma treatment. Ascorbic acid decreased significantly during long-term treatment with DBD plasma. To ensure the quality of lettuces during processing, the treatment time was shortened to 120 s. Under this condition, the degradation efficiency of malathion (0.5 mg kg −1) and chlorpyrifos (1.0 mg kg −1) on lettuces was found to be 53.1% and 51.4%. More importantly, we noted that cold plasma treatment significantly inactivated the microorganisms on lettuces. CONCLUSION: The results of the present study show that cold plasma is an effective and safe method for the degradation of organic pesticide residues on fresh vegetables at the same time as retaining the original quality.

Effect of Plasma-Activated Solution Treatment on Cell Biology of Staphylococcus aureus and Quality of Fresh Lettuces

“…A colorimeter (Color difference meter, CR-400, Konica-Minolta, Tokyo, Japan) was used to evaluate changes in the color of lettuce leaves after treatments. The total viable bacteria count, the content of vitamin C, and chlorophyll were determined according to the methods reported in our previously published study [ 22 ]. For SEM images of lettuce leaves, samples after treatment were cut into 2 mm × 2 mm and fixed in 2.5% glutaraldehyde solution.…”

The Application of Cold Plasma Technology in Low-Moisture Foods

“…For example, it is used for inactivating Salmonella , Listeria monocytogenes , and Duran virus [ 37 ], and removing aflatoxin B-1 from contaminated corn [ 38 ]. The application of CP technology has also been expanded to dissipation of agrochemical residues [ 39 ], such as the removal of malathion and chlorpyrifos on vegetables [ 40 , 41 ], and the reduction of azoxystrobin residues on strawberry fruit [ 42 ]. CP can modify the physicochemical properties of food materials.…”

Recent Advances and Potential Applications of Atmospheric Pressure Cold Plasma Technology for Sustainable Food Processing

“…The treatment did not significantly affect grape properties such as vitamin C, sugar content, color, and firmness. In 2020, Cong and collaborators used a DBD cold plasma device for the degradation of malathion and chlorpyrifos in lettuce, obtaining a degradation yield of 53.1% and 51.4%, respectively [19]. Additionally, the authors analyzed the degradation pathways of both compounds.…”