Inhibitory effect of essential oils on the growth of geotrichum candidum

Abstract

aim of this study was focused on the determination of the inhibitory effect of selected essential oils on the growth of five isolates of Geotrichum candidum. The isolates were obtained from the dairy products of domestic origin (sour cream, raw cow's milk, base for production of the brand, unsalted cheese, and cheese made from cows' milk). We studied the impact of five essential oils [pure essential oil EOs (100 %)]-clove, basil, rosemary, fennel and thyme at concentration of 0.625 μL. cm-3 of air. Gas chromatography-mass spectrometry (GC-MS) analysis was used for the identification of the main components of EOs. We tested the effect of the essential oils by the gaseous diffusion method. The isolates were cultivated on PDA (Potato dextrose agar), in the dark, at 25 ±1 °C, 14 days. The diameter growing of colonies we continuously measured on the 3rd, 7th, 11th, and 14th day of cultivation. The results of the paper suggest that clove and thyme essential oil had 100 % inhibitory effect on the growth of all tested isolates. Fennel, basil and rosemary essential oil had not significant inhibitory effects on tested isolates Geotrichum candidum. However, these oils affected the growth of colonies throughout the cultivation. Fennel EO had 100 % inhibition only on the growth of one isolates of Geotrichum candidum to the 3rd day of cultivation. Basil EO had the stimultating effect on the growth of two isolates of G. candidum (KMi 322 and KMi 189). Our results showed that clove and thyme essential oil could be used as a natural preservative useful in the food industry.