Inhibitory activity of the onion essential oil on growth Cladosporium cladosporioides, Emericella nidulans, and Eurotium spp.

Abstract

This study was aimed at investigating the antifungal potential of onion (Allium cepa L. cultivar Kupusinski jabučar) essential oil against Cladosporium cladosporioides, Emericella nidulans, and Eurotium spp. isolated from food. The antifungal determination of onion essential oil was performed using the agar plate method. Applied concentrations of the onion essential oil (3.5, 7.0, 14.0, and 28.0 μL/100 mL) caused the delay or absence of fungal growth with different inhibitory effects on deceleration in the growth rate. Onion essential oil at a concentration of 14.0 μL/100 mL demonstrated a fungicidal effect (MFC) on the growth of C. cladosporioides and Eurotium spp. and inhibitory effect (MIC) for E. nidulans, while at a concentration of 28.0 μL/100 mL showed MFC on the growth of E. nidulans. Microscopic investigations showed that the application of onion essential oil caused changes in micromorphology of the investigated fungi (hyphae and reproductive organs deformation). This study proved that the tested onion essential oil could potentially be used as a protective agent against food-borne fungi.

Ova studija imala je za cilj da ispita antifungalni potencijal etarskog ulja crnog luka (Allium cepa L. kultivar Kupusinski jabučar) prema Cladosporium cladosporioides, Emericella nidulans, Eurotium amstelodami, E. herbariorum, E. chevalieri i E. rubrum izolovanih iz hrane. Antifungalna ispitivanja izvedena su metodom agar ploča. Primenjene koncentracije etarskog ulja crnog luka (3,5; 7,0; 14,0 i 28,0 μL/100 mL) uzrokovale su izostanak ili odlaganje rasta gljiva, sa različitim inhibitornim delovanjem na brzinu rasta. Koncentracija etarskog ulja od 14,0 μL/100 mL bila je fungicidna (MFC) za C. cladosporioides, E. amstelodami, E. herbariorum, E. chevalieri, E. rubrum i inhibitorna (MIC) za E. nidulans. Koncentracija od 28,0 μL/100 mL fungicidno (MFC) je delovala na E. nidulans. Mikroskopska posmatranja su pokazala da je pod uticajem etarskog ulja crnog luka došlo do mikromorfoloških deformacija gljiva (deformacije hifa i reproduktivnih organa). Ova istraživanja su pokazala da se ispitivano etarsko ulje crnog luka može koristiti kao potencijalni zaštitni agens protiv fungalne kontaminacije hrane.