Combined Effect of Atmospheric Cold Plasma and Zataria multiflora Essential Oil Boiss. on the Growth Inhibition of Aspergillus flavus in Iranian White Cheese and Evaluation of its Sensory Properties

Cheese is recognized as a source of foodborne illness worldwide.

In this study, the growth inhibition of Aspergillus flavus inoculated on Iranian white cheese was investigated using cold atmospheric plasma and Zataria multiflora essential oil individually and in combination along with their effect on the sensory properties of cheese .

Slices of cheese cut in the presence and absence of 100 ppm of Zataria multiflora essential oil were exposed to cold atmospheric plasma for 2 and 5 minutes and stored in a refrigerator for 60 days. Afterwards, they were incubated in 5 time intervals (days 0, 15, 30, 45 and 60) and each was evaluated over a period of 10 days at 25 °C.

Based on the results, the plasma inhibitory effect had a pattern dependent on the plasma flow time and the increase in the flow time reduced the radial growth rate of mold. At all times of plasma flow, a significant inhibitory effect was observed on the mold growth compared to the control group (P<0.05). In terms of growth inhibition percentage, the lowest inhibition was detected in the presence of essential oil alone and the highest inhibitory property resulted from 5 minutes of plasma flow with essential oil. There was no difference between the sensory properties of plasma-treated cheese and the essential oil in combination with those of plasma-treated samples alone. The findings also showed that the addition of essential oil had no effect on the sensory properties of cheese.

Gliding arc plasma has inhibitory effects on the growth of Aspergillus flavus mold in cheese without adverse sensory changes, but the conditions must be optimized for industrial applications.