Treatment pH-values*
Without Inoculation Inoculated with E.coli inoculation with S.aureus
Storage period ( days)
0 5 10 15 0 5 10 15 0 5 10 15
Plain Yoghurt 4.47 ± 0.02 4.14 ± 0.03 3.95 ± 0.01 4.03 ± 0.03 4.35 ± 0.02 4.10 ± 0.02 4.00 ± 0.02 4.03 ± 0.02 4.35 ± 0.02 4.09 ± 0.02 4.01 ± 0.01 4.03 ± 0.02
Yoghurt  Bb-12 4.34 ± 0.03 4.07 ± 0.04 3.98 ± 0.02 3.98 ± 0.01 4.25 ± 0.03 4.04 ± 0.02 3.87 ± 0.02 3.97 ± 0.02 4.31 ± 0.04 4.03 ± 0.03 3.83 ± 0.02 3.99 ± 0.02
Yoghurt  Bb - 46 4.34 ± 0.03 4.08 ± 0.01 3.95 ± 0.02 3.95 ± 0.02 4.32 ± 0.02 4.07 ± 0.02 3.90 ± 0.02 4.01 ± 0.00 4.28 ± 0.03 4.07 ± 0.03 3.99 ± 0.01 3.99 ± 0.01
Soy yoghurt Bb-12 4.90 ± 0.03 4.84 ± 0.04 4.79 ± 0.01 4.71 ± 0.03 4.97 ± 0.02 4.79 ± 0.02 4.72 ± 0.01 4.76 ± 0.02 4.54 ± 0.03 4.62 ± 0.01 4.61 ± 0.02 4.63 ± 0.03
Soy yoghurt -Bb- 46 4.46 ± 0.02 4.41 ± 0.02 4.34 ± 0.01 4.37 ± 0.02 4.50 ± 0.02 4.37 ± 0.01 4.36 ± 0.03 4.05 ± 0.59 4.35 ± 0.03 4.37 ± 0.03 4.36 ± 0.03 4.35 ± 0.03
* Means values ( ± SD; n=3)
Table 2: Changes in pH –values of probiotic yogurt and soy-yogurt inoculated with Escherichia coli and Staphylococcus aureus during refrigerated storage period.