Preliminary studies on microbial management efficiency of ozonated water on Italian ready-to-eat table grape variety

Consiglio per la Ricerca in Agricoltura e l’Analisi dell’Economia Agraria - Centro di Ricerca Viticoltura ed Enologia (CREA-VE), Via Casamassima 148, 70010 Turi, Italy

Abstract

Ozonated water is an alternative means of post-harvest fruit and vegetable management that keeps gaining interest for its applications. The aim of this study was to evaluate the effects of ozonated water at different concentrations (12 mg L^-1 and 8 mg L^-1) on ready-to-eat Italian ‘Regal seedless’ grapes, to assess the ozone effect on grey mould and berry microbiome (non-Saccharomyces yeasts, total bacteria, and total fungi). An ozone generator capable of producing ozone concentration ranging from 18 to 65 Nm³ was used to obtain the different ozone concentration levels in water where berries were immersed. After 26 days of cold storage, grey mould incidence was assessed as percentage ratio between the number of affected berries and the total number of berries. Berries dipped into ozonated water at the higher ozone concentration of 12 mg L^-1 showed a 61% average reduction of the overall disease incidence compared to the control. Moreover, the microbiome of berries treated with 12 mg L^-1 ozone concentration showed significant reduction of fungal and yeast populations, while not showing any significant difference for the bacterial population, compared to the control.