Efficacy of Origanum vulgare L. and Rosmarinus officinalis L. essential oils in combination to control postharvest pathogenic Aspergilli and autochthonous mycoflora in Vitis labrusca L. (table grapes)

• OVEO and ROEO combined at sub-MICs inhibited A. flavus and A. niger.
• OVEO and ROEO at sub-MICs inhibited naturally occurring fungi in grapes.
• OVEO and ROEO at sub-MICs preserved the quality of grapes during storage.

This study evaluated the efficacy of the application of the essential oils of Origanum vulgare L. (OVEO) and Rosmarinus officinalis L. (ROEO) alone and in combination to inhibit Aspergillus flavus URM 4540 and Aspergillus niger URM 5842 in fungal growth media and on Vitis labrusca L. (table grapes). The influence on the autochthonous mycoflora and the physical, physicochemical and sensory characteristics of the grapes during storage (25 °C, 12 days and 12 °C, 24 days) were also studied. The application of the essential oils in different concentrations (Minimum Inhibitory Concentration — MIC, 1/2 MIC + 1/2 MIC and 1/4 MIC + 1/4 MIC) inhibited the mycelial growth and spore germination of the test fungi and inhibited the growth of the assayed fungal strains in artificially contaminated grapes and the autochthonous mycoflora of grapes stored at both room and cold temperatures. In general, the application of OVEO and/or ROEO at sub-lethal concentrations preserved the quality of grapes as measured by their physical, physicochemical and sensory attributes throughout the assessed storage time. These results demonstrate the potential of the combination of OVEO and ROEO at sub-lethal concentrations to control postharvest pathogenic fungi in fruits, particularly, A. flavus and A. niger in table grapes.