Caracterización química, variabilidad composicional y modelamiento matemático del efecto de aceites esenciales en Alternaria alternata.

Mathematical models of in vitro growth and germination of Alternaria alternata in the presence of essential oils were developed. By using principal component analysis, similarities were found among the oils in terms of their volatile composition. The mycelial growth and conidial germination of A. alternata was evaluated in PDA with cinnamon, epazote and lime oils (0.25, 0.5 and 1.0 μL mL-1). The oils used were obtained by hydrodistillation and commercially and were characterized by gas chromatographymass spectrometry. The Baranyi and Roberts and logistics equations were used to fit the experimental data and to predict its behavior. Due to their chemical composition, the oils were grouped into: 1) cinnamon (commercial and non-commercial), in which cis-cinnamaldehyde predominated, 2) commercial lime (D-limonene) and epazote (commercial and non-commercial) with ascaridole and ρ-cimene, and 3) non-commercial lime. Cinnamon oil (0.5 and 1.0 μL mL-1) inhibited mycelial growth of A. alternata, whereas germination was 100 % inhibited with the presence of lime and epazote oils (0.25 and 0.5 μL mL-1). Mathematical models and principal component analyses are effective tools for understanding the effect of essential oils on A. alternata. [ABSTRACT FROM AUTHOR]