*Article* **Chemical Composition and Antimicrobial Properties of** *Mentha × piperita* **cv. 'Kristinka' Essential Oil**

**Ippolito Camele 1, Daniela Grul'ová <sup>2</sup> and Hazem S. Elshafie 1,\***


**Abstract:** Several economically important crops, fruits and vegetables are susceptible to infection by pathogenic fungi and/or bacteria postharvest or in field. Recently, plant essential oils (EOs) extracted from different medicinal and officinal plants have had promising antimicrobial effects against phytopathogens. In the present study, the potential microbicide activity of *Mentha* × *piperita* cv. 'Kristinka' (peppermint) EO and its main constituents have been evaluated against some common phytopathogens. In addition, the cell membrane permeability of the tested fungi and the minimum fungicidal concentrations were measured. The antifungal activity was tested against the following postharvest fungi: *Botrytis cinerea*, *Monilinia fructicola*, *Penicillium expansum* and *Aspergillus niger*, whereas antibacterial activity was evaluated against *Clavibacter michiganensis*, *Xanthomonas campestris*, *Pseudomonas savastanoi* and *P. syringae* pv. *phaseolicola*. The chemical analysis has been carried out using GC-MS and the main components were identified as menthol (70.08%) and menthone (14.49%) followed by limonene (4.32%), menthyl acetate (3.76%) and β-caryophyllene (2.96%). The results show that the tested EO has promising antifungal activity against all tested fungi, whereas they demonstrated only a moderate antibacterial effect against some of the tested bacteria.

**Keywords:** medicinal plants; GC-MS; postharvest diseases; biological control; cell membrane permeability
