Abstract Three concentrations (3, 5, and 7 ml/100g retentate) of each of three natural oils were added during
manufacturing of low salt white cheese. The mycobiota of cheese were assessed after 8 hours, 3 weeks, 7 weeks and 11 weeks.
Twelve species were isolated (Aspergillus flavus, A. fumigatus, A. niger, A. versicolor, Penicillium aurantiogriseum, P.
camembertii, P. griseofulvum, P. islandicum, P. oxalicum, P. restrictum, Ulocladium atrum and the yeast species
Debaryomyces hansenii). The total counts of fungi increased in Laurus nobilis oil-treated cheese at the three concentrations
after 3 weeks compared with control, but decreased after 7 weeks in treatment with 3 and 7% of oil concentrations. Cheese
treated with Anethum graveolens oil at 3% concentration showed the highest fungal counts after 7 weeks of storage. The
fungal counts decreased by increasing all concentrations of Mentha piperita oil (3, 5 and 7%). Generally, treatment of cheese
with M. piperita oil significantly decreased the total counts of fungi. On the other hand, oils of L. nobilis and A. graveolens at
3 to 7% concentrations caused an increase of total counts after 3 and 11 weeks but L. nobilis and A. graveolens oils caused a
decrease after 7 weeks at 5 and 7% concentrations compared to control,. Isolates of Aspergillus flavus screened for aflatoxin
production using Coconut agar medium (CAM) were positive foraflatoxin B production when observed at 365 nm UV light.