Effect of some plant essential oils on the fungal population of industrial white cheese

This study carried out to determine the antifungal effect of some plant essential oils (Thyme, Tarragon, Caraway seed, Peppermint and Pennyroyal) on industrial white cheese. Two concentrations (0.3 & 0.4 %) were added in white cheese, which their fungal population was determined previously. For comparison purpose, identical cheese sample without any essential oils were chosen as control groups.All of the samples and controls were kept in 12 oC for 2 weeks, and checked for fungal population at 72, 168 and 336 h intervals. The results showed that the population of fungi grew in control groups and reached to a level of 104 cfu/g after 336 h, but in treatment groups the essential oils of the examined plants showed desirable antifungal effect. The essential oils of the Thyme and Tarragon showed the most effective antifungal activity and inhibited the growth of fungal population completely, where as the others could not control the growth of fungi completely, although the final fungal population after 336 h were within the standard range (102 cfu/g). With regard to our finding, the essential oils of the examined plants have desirable antifungal effect on cheese and can probably be used as a natural preservative in foods.