Table 2.
Changes in pH and growth of microorganisms during 30-day storage (4 °C) of cooked beef sausage (CBS) treated by preservations
| Measured factor | Sample | 0 day | 8 days | 15 days | 22 days | 30 days |
|---|---|---|---|---|---|---|
| pH | CBSC | 6.08 ± 0.07 | 6.12 ± 0.12 | 6.41 ± 0.09 | 6.79 ± 0.09 | 7.01 ± 0.12 |
| CBS1 | 6.12 ± 0.11 | 5.92 ± 0.06 | 5.90 ± 0.14 | 6.12 ± 0.11 | 6.17 ± 0.08 | |
| CBS2 | 6.14 ± 0.13 | 6.10 ± 0.21 | 6.08 ± 0.11 | 6.12 ± 0.12 | 6.18 ± 0.14 | |
| CBS3 | 6.03 ± 0.10 | 5.86 ± 0.13 | 5.91 ± 0.12 | 5.98 ± 0.09 | 6.11 ± 0.11 | |
| CBS4 | 6.14 ± 0.08 | 5.98 ± 0.13 | 6.12 ± 0.15 | 6.17 ± 0.12 | 6.19 ± 0.16 | |
| CBS5 | 6.18 ± 0.12 | 6.07 ± 0.08 | 6.14 ± 0.12 | 6.20 ± 0.10 | 6.27 ± 0.11 | |
| Clostridium perfringens (logcfu/g) | CBSC | < 1.7* | 4.34 ± 0.42 | 4.3 ± 0.71 | 5.63 ± 1.31 | 7.61 ± 0.74 |
| CBS1 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | 3.81 ± 0.61 | |
| CBS2 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | |
| CBS3 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | 1.83 ± 0.96 | |
| CBS4 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | |
| CBS5 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | < 1.7 | |
| Coliform (logcfu/g) | CBSC | < 1 | 2.42 ± 2.11 | 3.87 ± 0.71 | 6.87 ± 1.09 | 12.39 ± 2.87 |
| CBS1 | < 1 | < 1 | < 1 | < 1 | < 1 | |
| CBS2 | < 1 | < 1 | < 1 | < 1 | < 1 | |
| CBS3 | < 1 | < 1 | < 1 | < 1 | < 1 | |
| CBS4 | < 1 | < 1 | < 1 | < 1 | 1.8 ± 0.78 | |
| CBS5 | < 1 | < 1 | 2.41 ± 0.82 | 2.62 ± 0.29 | 3.01 ± 0.73 | |
| Total count | CBSC | 3.4 ± 0.1 | 4.2 ± 0.0 | 5.2 ± 0.0 | 7.3 ± 0.0 | 6.2 ± 0.0 |
| CBS1 | 3.9 ± 0.1 | 4.6 ± 0.0 | 5.2 ± 0.0 | 6.3 ± 0.1 | 5.9 ± 0.1 | |
| CBS2 | 2.5 ± 0.1 | 3.6 ± 0.0 | 4.7 ± 0.1 | 5.9 ± 0.1 | 5.1 ± 0.1 | |
| CBS3 | 2.8 ± 0.1 | 3.7 ± 0.1 | 4.2 ± 0.1 | 5.1 ± 0.0 | 4.8 ± 0.1 | |
| CBS4 | 3.1 ± 0.1 | 5.1 ± 0.1 | 5.7 ± 0.1 | 6.2 ± 0.0 | 6.1 ± 0.1 | |
| CBS5 | 4.0 ± 0.1 | 3.9 ± 0.2 | 5.1 ± 0.1 | 6.5 ± 0.1 | 5.6 ± 0.0 | |
| Mold and yeast | CBSC | 0 | 2.4 ± 0.1 | 3.2 ± 0.1 | 3.4 ± 0.1 | 4.3 ± 0.0 |
| CBS1 | 0 | 0.7 ± 0 | 1.5 ± 0.1 | 2.2 ± 0.0 | 2.8 ± 0.0 | |
| CBS2 | 0 | 0 | 0 | 0 | 0 | |
| CBS3 | 0 | 0 | 1.2 ± 0.1 | 1.9 ± 0.1 | 2.1 ± 0.0 | |
| CBS4 | 0 | 1.0 ± 0.0 | 1.3 ± 0.0 | 1.7 ± 0.0 | 2.6 ± 0.1 | |
| CBS5 | 0 | 1.7 ± 0.1 | 2.7 ± 0.1 | 3.1 ± 0.0 | 3.8 ± 0.1 |
CBSC, CBS1, CBS2, CBS3, CBS4 and CBS5 represent CBS without preservation, treated by 120 ppm nitrite, 90 ppm nitrite and 50 ppm lupulon–xanthohumol nanoliposome (L–X-NL), 60 ppm nitrite and 100 ppm L–X-NL, 30 ppm nitrite and 150 ppm L–X-NL, and 200 ppm L–X-NL, respectively
*The maximum acceptable CFU/g for C. perfringens and coliform is 1.7 and 1, respectively