Efficacy of alkaline and acidic electrolysed water generated by some salt solutions against gray mold of table grape: pre and postharvest applications

The objectives of the this research were to assess the activity of alkaline (alEW) and acidic electrolysed water (acEW), in vitro and in vivo, against the development of gray mold caused by Botrytis cinerea Pers. on table grape cv. Crimson seedless and to investigate these treatments on grape quality. Thirteen salt solutions (potassium bicarbonate, potassium sorbate, sodium silicate, EDTA-Fe, EDTA-Ca, sodium bicarbonate, sodium carbonate, potassium carbonate, potassium phosphate dibasic, potassium dihydrogen phosphate, ammonium molybdate, sodium metabisulphite, sodium chloride), most of them are generally recognized as safe (GRAS) compounds, were used to generate alEW and acEW. In vitro results showed that in alEW, sodium carbonate and potassium sorbate were the most effective salts reducing the percentage of colony forming units (CFUs) by 67.3 and 63.7%, respectively. In acEW, sodium carbonate, potassium bicarbonate, sodium silicate, potassium sorbate and EDTA-Fe were the most effective salts reducing CFUs by 88, 86, 85, 89 and 84%, respectively. Under artificial infection, at the end of cold storage, for alEW, the percentage of reduction ranged from 55-91.7% and potassium carbonate gave the best results against the grapes gray mold (91.7%). For acEW, the percentage of reduction ranged from 77-98% and ammonium molypdate gave the best results against gray mold (98%). Electrolysed water generated by potassium sorbate, sodium carbonate and sodium metabisulphite was effective against development of gray mold disease under natural infection. In most cases, the results of the present research showed that alEW and acEW did not influence the physicochemical properties of berry quality. This study confirms that electrolysed water is an effective treatment and has a good control activity against gray mold of table grape and it demonstrates that certain salts improve the electrolysis potential.Â