DiaClean® water technology for the postharvest preservation of citrus fruits causes no cytotoxic effect after air-drying and storage

Abstract

Citrus fruits are one of the most important sources of income in many countries and are widely cultivated in the Mediterranean area. During postharvest packing, storage and transportation, citrus fruits can be infestated by a variety of diseases such as mold infection. Thus, the control of postharvest disease is essential for the quality and shelf-life of citrus fruits.In this present study, the DiaClean® water technology which is based on the electrolysis of a 1.25% NaHCO 3 solution with boron-doped diamond electrodes as an alternative to the treatment of citrus fruits with fungicides, was used for fruit preservation. Aliquots of the total mixtures of compounds generated at different stages of the process were used to investigate their cytotoxic effects as an indicator for the evaluation of human health and environmental risks. Cultured connective tissue fibroblasts (cell line L-929) were used for the assays and cell vitality was checked by measurement of the enzymatic activity of mitochondrial dehydrogenases within the cells.The results clearly demonstrate that the use of electrolyzed NaHCO 3 in the preservation of citrus fruits is very effective in the acute stage of electrolysis; the occurrence of antimicrobial and cytotoxic compounds is limited to the liquid stages of the process. After air-drying, no cytotoxic effect was observed which might be harmful to human health and the environment. Abbreviations: BDD: Boron-doped diamond electrodes, ROS:reactive oxygen species IntroductionCitrus fruits are one of the most important sources of income in many countries and are widely cultivated in the Mediterranean area. During postharvest packing, storage and transportation, which may take several weeks, citrus fruits can be infestated by a variety of diseases. Among these, the disease caused by a green mold Penicillium digitatum is one of the most serious ones and might cause up to 90% of product losses [1]. Thus, the control of postharvest disease is essential for the quality and shelf-life of citrus fruits.The use of various fungicides and herbicides such as imazalil (fungicide), thiabendazole (fungicide and herbicide), pyrimethanil (fungicide) and others has minimized postharvest infestation [2], but the extensive application has led to resistant strains, which decrease their effectiveness. In addition, human health and environmental risks are associated with the use of such fungicides [3]. As a matter of fact, alternative strategies which combine effectiveness and low health and environmental risks have been developed during the last years.One of the very promising technologies for this problem seems to be the use of electrolyzed water which has been tested successfully in food industrial processes [4] and against postharvest decay of fresh fruits and vegetables [5][6][7]. Thus, the use of Boron Doped Diamond (BDD) electrodes for electrolysis of citrus fruit wash water proved to be effective and could be increased by the addition of NaHCO 3 to the Dartsch PC (2017) DiaClean® water technology for the post...

Electrochemical degradation of surfactants in domestic wastewater using a DiaClean® cell equipped with a boron-doped diamond electrode

“…Nevertheless, the nature of anode materials plays an important role in the treatment efficiency, degradation mechanism, and selectivity ( Espinoza et al, 2021 ; He et al, 2022 ). The BDD has demonstrated high efficacy compared to other types of electrodes owing to its wide electrochemical potential window, good chemical/electrochemical stability, and strong corrosion resistance ( Armijos-Alcocer et al, 2017 ; Espinoza-Montero et al, 2013 , 2022Rabbani et al, 2017 ) because of which this diamond electrode has been recognized as the most efficient and ideal anode material, which has been extensively investigated for the degradation of organic contaminants in aquatic environments ( C. Dartsch & Pupunat, 2017 ; Carrera-Cevallos et al, 2021 ; Espinoza-Montero et al, 2022 ; He et al, 2022 ; Oturan & Oturan, 2018 ).…”