## 3 Results and Discussion
### Shelf-Life Study
#### 3.1.4 Other Indices--Color/pH/Sensory Attributes
The average b* values of the samples during storage were 2.57 \(\pm\) 0.27, 5.37 \(\pm\) 0.27, 4.32 \(\pm\) 0.22 and 4.64 \(\pm\) 0.31 for the CNT, RN, RSE and RSE-RSME samples, respectively. This 'clustering' of samples, regarding their yellowish tone, is also indicated in Figure 5b. Overall, the color results indicate that while the treated samples exhibit similar lightness and redness to the control samples, despite containing half the amount of nitrites, they are slightly more yellowish than the control (CNT) samples. Nevertheless, the RSE samples seem to simulate control samples' color in a satisfactory way. Similar results were also obtained at the other storage temperatures (10 and 15 \({}^{\circ}\)C). The sensory characteristics (appearance and odor) of the control and extract-enriched bacon samples were evaluated, and the representative results are presented in Figure 6. A slight decrease in the sensory scores of appearance was observed in all samples during the storage time, due to the slight yellowish tone (Figures 5b and 7). However, all samples remained acceptable after 49 days of storage under chilled conditions in vacuum-sealed packaging, as none of them received a score below 5, which was considered the minimum threshold for acceptability. The final scores for appearance at 49 days of storage were 7.5 \(\pm\) 0.2, 6.4 \(\pm\) 0.4, 7.0 \(\pm\) 0.4 and 6.2 \(\pm\) 0.3 for the CNT, RN, RSE and RSE-RSME samples, respectively, indicating that the control samples (CNT) received the highest score, followed closely by the RSE samples, while the RSE-RSME samples received the lowest score. The sensory scores for odor also decreased with storage time in all samples, with the control samples retaining their odor for longer, followed closely by the RSE samples. Over time, the smell without being unpleasant was more intense compared to the samples measured during the first days of chilled storage. This should be attributed to the proteolysis taking place [46], as well as to the volatile metabolic products of the bacteria, which, due to the low permeability of the packaging material, do not escape into the atmosphere and remain inside the food. As described in [47], using metabolomic studies, the action of endogenous enzymes (e.g., proteases) and spoilage microorganisms during the chilled storage of bacon  
Figure 5: Color changes expressed with (**a**) a values (CIELab) and (**b**) combined a and b values of bacon samples (CNT: control samples, RN: reduced-nitrite samples, RSE: reduced-nitrite samples enriched with rose extract, RSE-RSME: reduced-nitrite samples enriched with rose and rosmary extract). Error bars represent the \(\pm\) standard deviation of measurements. leads to the decomposition of proteins and fats, gradually forming aldehydes, ketones, alcohols, esters, acids, and other off-flavor compounds. More specifically, the CNT samples remained acceptable in terms of their sensory attributes until the end of the 49-day storage period, reaching a minimum score of 5.0 \(\pm\) 0.2. The RSE samples reached a minimum score of 4.3 \(\pm\) 0.4 at the end of the storage period and remained sensorily acceptable until day 41 of storage. On the other hand, the RSE-RSME and RN samples' odor deteriorated, reaching a final score of 2.2 \(\pm\) 0.2 and 2.0 \(\pm\) 0.4, respectively, surpassing the limit score of 5 by day 29 of storage. Overall, the bacon samples enriched with rose extract (RSE) retained their sensory attributes as effectively as the control samples. However, the RSE-RSME samples, enriched with both rose and rosemary extract, maintained their sensory acceptability for a shorter time, exhibiting a behavior similar to samples containing half the nitrite amount (RN). Similar results were also observed at the other storage temperatures (10 and 15 \({}^{\circ}\)C), with the sensory characteristics of the samples exceeding their limits in a shorter period of time due to more rapid microbial spoilage.