Effect of Adding Different Concentrations of Thyme oil on reducing the total microbial count in the soft cheese to increase the shelf life

The thyme oil was added to the milk that processed into soft cheese in a concentration of (1 ml thyme oil /1000 ml milk (T2), 2 ml thyme oil/ 1000 ml milk (T3), 3ml thyme oil / 1000 ml milk (T4) in addition to the control treatment no thyme oil added (T1). All the treatments were stored at a temperature of 7̊C for four weeks. A total count numbers of the microorganisms and coli form bacteria were determined in addition to the sensory evaluation of the soft cheese samples that added to them different concentrations of thyme oil. The results indicated that there was a significant difference between treatments where the total count numbers of microorganisms significantly decreased as the addition of thyme oil increased also the results represented that there was a significant increase in the total count numbers of the microorganisms as the storage period increased for the control treatment while this increased in the number was decreased in the samples with thyme oil where this development of microorganisms decreased by increasing the addition of thyme oil. For the sensory evaluation for both the color and flavor, the results indicated that there was no significant differences between the control treatment ( T1) and treatments (T2) and (T3) and also there were no significant differences between (T3) and (T4) but there was a significant difference between treatments (T1, T2 and T3) and treatment (T4). While for texture and cohesion, there were no significant differences between treatments. In terms of general acceptance, there were significant differences between the control treatment (T1) and (T4) while there was no significant differences between the control treatment (T1) and treatments (T2) and (T3) and also there were no significant differences between treatments (T2, T3, and T4).

کلیدواژه ها:

soft cheese ، thyme oil ، Coliform bacteria ، Total count bacteria