TABLE 2.
Changes in viable counts of bacon inoculated with potential spoilage bacteria, during refrigerated storage after 45 days.
| Colony and selective medium | Storage time (days) | Microbiological analysis (log10 CFU/g) | ||||||
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| CK | P2 | P6 | P9 | P16 | P20 | Pm | ||
| TVC (PCA 30°C) | 0 | ND | / | / | / | / | / | / |
| 7 | ND | 6.50 ± 0.66d | 6.41 ± 0.72c | 6.71 ± 0.47c | 6.31 ± 0.62c | 6.51 ± 0.44d | 6.94 ± 0.52c | |
| 15 | ND | 8.05 ± 0.37c | 8.21 ± 0.73b | 8.02 ± 0.58b | 8.17 ± 0.71b | 7.99 ± 0.66c | 8.09 ± 0.82b | |
| 22 | ND | 8.34 ± 0.84bc | 8.72 ± 0.96ab | 8.79 ± 0.85ab | 8.76 ± 0.65a | 8.37 ± 0.47b | 8.61 ± 1.24ab | |
| 30 | ND | 9.01 ± 1.13a | 8.91 ± 1.05a | 9.07 ± 1.21a | 8.64 ± 0.84ab | 8.66 ± 0.86ab | 8.97 ± 0.99a | |
| 45 | ND | 8.86 ± 0.99b | 8.64 ± 1.12ab | 8.74 ± 0.66ab | 8.34 ± 0.93ab | 8.78 ± 0.95a | 8.72 ± 0.85ab | |
| TVC (PCA 7°C) | 0 | ND | / | / | / | / | / | / |
| 7 | ND | 6.48 ± 1.20d | 6.52 ± 0.46c | 6.52 ± 0.48c | 6.72 ± 0.59c | ND | 6.22 ± 1.24c | |
| 15 | ND | 8.00 ± 0.42c | 8.04 ± 0.87b | 7.86 ± 0.67b | 7.55 ± 0.82b | 5.12 ± 0.47c | 7.74 ± 0.48b | |
| 22 | ND | 8.21 ± 0.77b | 8.27 ± 0.64ab | 8.38 ± 0.57ab | 8.62 ± 0.57ab | 6.35 ± 0.61b | 8.65 ± 1.08a | |
| 30 | ND | 8.83 ± 0.94a | 8.75 ± 0.95a | 8.67 ± 0.91a | 8.93 ± 1.25a | 6.16 ± 0.79b | 8.51 ± 1.22ab | |
| 45 | ND | 8.61 ± 0.88ab | 8.42 ± 0.58ab | 8.59 ± 0.86ab | 8.01 ± 0.76ab | 6.58 ± 0.92a | 8.62 ± 0.86ab | |
| LAB (MRS) | 0 | ND | / | / | / | / | / | / |
| 7 | ND | ND | 6.37 ± 0.77c | ND | ND | ND | 5.61 ± 0.51e | |
| 15 | ND | 4.15 ± 0.56c | 8.33 ± 0.59b | 5.20 ± 0.42c | 5.67 ± 0.47c | ND | 5.84 ± 0.63d | |
| 22 | ND | 3.17 ± 0.56c | 9.06 ± 1.36a | 8.05 ± 0.76ab | 7.89 ± 0.58b | 4.64 ± 0.39 | 6.85 ± 0.77c | |
| 30 | ND | 7.12 ± 0.58b | 8.88 ± 0.67ab | 8.42 ± 0.81a | 8.21 ± 0.67a | 5.75 ± 0.41 | 7.22 ± 0.68b | |
| 45 | ND | 7.79 ± 0.91a | 8.74 ± 0.85b | 7.89 ± 0.98ab | 8.20 ± 1.17ab | 5.39 ± 0.74 | 7.68 ± 0.49a | |
| Staphylococcaceae (BP) | 0 | ND | / | / | / | / | / | / |
| 7 | ND | 3.12 ± 0.55e | ND | 7.01 ± 0.82c | 5.43 ± 0.92c | ND | 5.87 ± 0.87c | |
| 15 | ND | 4.87 ± 0.63d | ND | 8.02 ± 0.86b | 6.92 ± 0.43b | ND | 7.89 ± 0.75b | |
| 22 | ND | 5.30 ± 1.12c | ND | 8.87 ± 1.34ab | 7.46 ± 0.66ab | ND | 8.46 ± 0.60a | |
| 30 | ND | 7.48 ± 0.58b | ND | 9.01 ± 0.68a | 7.75 ± 0.57a | ND | 7.84 ± 0.63b | |
| 45 | ND | 8.21 ± 0.58a | ND | 8.64 ± 1.24ab | 6.07 ± 0.85ab | ND | 8.24 ± 0.88ab | |
| Enterobacteriaceae (VRBGA) | 0 | ND | / | / | / | / | / | / |
| 7 | ND | 5.94 ± 0.41d | ND | 2.41 ± 0.35d | 5.27 ± 0.38d | 6.41 ± 0.74d | 4.47 ± 0.57a | |
| 15 | ND | 7.92 ± 0.87c | 4.53 ± 0.42c | 4.27 ± 0.48bc | 7.72 ± 0.57b | 7.39 ± 0.87c | 6.47 ± 0.86a | |
| 22 | ND | 8.32 ± 1.08b | 8.48 ± 1.05b | 4.65 ± 0.55c | 7.52 ± 1.30c | 8.22 ± 1.18ab | 7.24 ± 1.02a | |
| 30 | ND | 8.46 ± 0.94a | 8.57 ± 1.24ab | 6.92 ± 0.64b | 8.67 ± 0.71a | 8.16 ± 1.22b | 8.66 ± 1.42a | |
| 45 | ND | 8.62 ± 0.59ab | 8.28 ± 0.86a | 7.78 ± 0.97a | 8.28 ± 0.99ab | 8.49 ± 0.87a | 8.53 ± 1.04a | |
Means with different letters within the same column indicate a significant difference at P < 0.05.
CK, control samples; P2, Staphylococcus xylosus; P6, Leuconostoc mesenteroides; P9, Carnobacterium maltaromaticum; P16, Leuconostoc gelidum; P20, Serratia liquefaciens; Pm, a mixture of these five strains.