The Antifungal Effect of Gaseous Ozone on Lasiodiplodia theobromae Causing Stem-End Rot in 'Keitt' Mangoes

This study evaluated the antifungal activity of ozone (O-3) against stem-end rot of mango fruit (cv. Keitt). Mango fruit were exposed to gaseous ozone (0.25 mg/L) for 24 or 36 h during cold storage, and control fruit were untreated. Experimental fruit were stored at 90% relative humidity and 10 +/- 0.5 degrees C for three weeks and ripened at ambient temperature for one week. Ozone treatment (24 h) inhibited the mycelial growth of Lasiodiplodia theobromae by 60.35%. At day twenty-eight of storage, fruit treated with O-3 for 36 h had low mass loss (%) and high firmness compared to the untreated control fruit. Treating mango fruit with O-3 (36 h) maintained the color and concentration of total flavonoids throughout the storage time. At the end of storage, peroxidase activity under the O-3 24 h treatment was significantly higher (0.91 U min(-1) g(-1) DM) compared to O-3 (36 h) and control, which, respectively, had 0.80 U min(-1) g(-1) DM and 0.78 U min(-1) g(-1) DM. Gaseous ozone for 24 h is recommended as a cost-effective treatment for controlling stem-end rot. These findings suggest that gaseous ozone effectively controlled stem-end rot and enhanced the postharvest quality of mango fruit.