EFFECT OF THYME AND NIGELLA SATIVA OILS ON PSEUDOMONAS AERUGINOSA EXPERIMENTALLY INOCULATED IN MINCED MEAT

This work was carried out to study the maximum effect of different concentrations of Thyme oil (0.04% and 0.06%) and Nigella sativa oil (1.5% and 2.5%) and mixture of Thyme and Nigella sativa oils (0.04% and 2.5%) respectively, on the viable count of Pseudomonas aeruginosa strain experimentally inoculated in minced meat (106cfu/g).The results revealed that Nigella sativa oils have a powerful effect on Pseudomonas aeruginosa and not affect the organoleptic CHARacters of the examined samples till the 8thday of storage comparing with the effect of Thyme oil as the signs of decomposition appeared and organoleptic changes occurred in the 6thday of storage. The inhibitory effect of these oils was tested by paper –disk diffusion method using different concentrations. The obtained results showed that the most inhibitory extract which gave the greatest zone of inhibition (8mm diameter) was the mixture of Thyme and Nigella sativa oils (0.04% and 2.5%)respectively, followed by (7mm diameter) Nigella sativa oil (2.5%)on the growth of Pseudomonas aeruginosa. Overall, the study concluded that Nigella sativa oil has a highly effect in reduction of the viable count of Pseudomonas aeruginosa to 5.6±0.52 log cfu/g without affecting the organoleptic CHARacters till the 8th day of storage.