Cold plasma-mediated inhibition of postharvest fungal communities of strawberries

Cold plasma is a promising non-thermal method for managing postharvest pathogens that cause mould and fruit decay. This study evaluated cold plasma (CP) and plasma-activated water (PAW) to control the postharvest fungal pathogens associated with strawberries. Fresh ‘Fronteras’ strawberries were treated with CP, PAW, or PAW applied as a mist (PAWM), and quality parameters, including spoilage, firmness, colour, and weight were measured on days 0 and 6. Propidium monoazide (PMA), a dye that selectively binds to the DNA of non-viable cells and prevents PCR amplification, was used to differentiate between viable and non-viable fungi following treatment. Strawberries treated with CP or immersed in PAW for 60 s had significantly reduced visible decay at day 6 without affecting fruit quality, but PAWM was ineffective at reducing spoilage. All treatments significantly reduced fungal diversity when measured using PMA-based metabarcoding after storing for 6 d at 4 °C, compared to the untreated control, with significantly lower abundance of viable fungi. Viable Cladosporium (strawberry pathogen) and Rhodotorula (biocontrol for berry fruit) accounted for 98 % of fungal communities in all treatments after 6 d. Differential abundance analysis showed that all treatments inhibited Filobasidium and Cystofilobasidium while reducing Botrytis abundance. These results demonstrate the potential of CP and PAW treatments to reduce fungal communities, including pathogens, and thus spoilage of postharvest strawberries. • Cold plasma (CP) and plasma-activated water (PAW) were tested on strawberries. • CP and PAW treatments for 60 s reduced spoilage without affecting fruit quality. • All plasma treatments inhibited Filobasidium and Cystofilobasidium . • Cladosporium and Rhodotorula dominated the viable fungal community after treatments. • CP and PAW treatments could be used to control postharvest pathogens.