## 3 Results and Discussion
### Shelf-Life Study
#### 3.1.4 Other Indices--Color/pH/Sensory Attributes  
Vacuum-packaged bacon slices, during their storage under chilled conditions (5, 10 and 15 \({}^{\circ}\)C), showed a slight decrease in pH values. The differences observed in pH values between the different types of samples (CNT, RN, RSE and RSE-RSME) were only marginal, and thus are considered as insignificant. At 5 \({}^{\circ}\)C, the average initial values for the CNT, RN, RSE and RSE-RSME samples were 5.93 \(\pm\) 0.06, 5.61 \(\pm\) 0.05, 5.51 \(\pm\) 0.06 and 5.64 \(\pm\) 0.08, respectively, while after 49 days of storage, the pH values decreased to 5.26 \(\pm\) 0.12, 5.12 \(\pm\) 0.04, 5.08 \(\pm\) 0.15, and 5.01 \(\pm\) 0.08, respectively. This reduction in pH values is attributed to the production of lactic acid due to the growth of lactic acid bacteria (LAB) during the storage of the samples under anaerobic conditions. Similar results were also obtained at the other storage temperatures (10 and 15 \({}^{\circ}\)C). The color changes of bacon samples during chilled storage (at 5 \({}^{\circ}\)C) are presented in Figure 5. The L* value, representing color brightness or lightness on a scale from 0 to 100 (where 0 stands for white and 100 for black), remained consistent for both treated and untreated samples throughout the 49-day storage period at 5 \({}^{\circ}\)C, showing no significant changes from day 0. The control samples seem to be the darkest samples and the RSE-RSME samples seem to be the brightest ones. The control samples (CNT) had an average L* value of 63.19 \(\pm\) 0.76 during the storage period and the RN, RSE and RSE-RSME samples had values of 67.22 \(\pm\) 0.63, 65.21 \(\pm\) 0.44 and 68.31 \(\pm\) 0.63, respectively. The a* axis represents the position of the color on the green to red spectrum, with positive a* values indicating red color, while negative values indicate green color. The a* values for all samples also remained stable during storage, with the RN and RSE-RSME samples displaying lower values and the RSE samples showing the highest values displaying more red tones. The average a* values of the samples during storage, depicted in Figure 5a (where a* values are presented cumulatively for all storage times, as distributions, for the different sample categories), were 8.85 \(\pm\) 0.12, 8.10 \(\pm\) 0.16, 9.72 \(\pm\) 0.27 and 7.85 \(\pm\) 0.34 for the CNT, RN, RSE and RSE-RSME samples, respectively. Hence, the treated samples using only rose by-products seem to present an enhanced red color, while the treated samples with rose and rosemary extract managed to maintain the red color of meat in comparison to the control (CNT) samples, both with half the amount of nitrites. It is worth noting that increased values of the color parameter a* have also been observed in bacon enriched with tea, apple, and cinnamon polyphenols [45]. Polyphenols are known antioxidants, meaning they have reducing properties. Their presence, as a reducing agent, favors the  
Figure 4: Average thiobarbituric acid reactive substance (TBAR) values for anaerobically packaged bacon slices during 49 days of storage at 5 \({}^{\circ}\)C (CNT: control samples, RN: reduced-nitrite samples, RSE: reduced-nitrite samples enriched with rose extract, RSE-RSME: reduced-nitrite samples enriched with rose and rosemary extract). Error bars represent the \(\pm\) standard deviation of measurements. conversion of nitrites into nitric oxide, which reacts with the main protein of the meat and forms nitrosomyoglobin, which has a bright red color that is stabilized after the mild heat treatment/smoking of the bacon. The b* axis represents the position of the color on the blue to yellow spectrum, with positive b* values indicating yellowness, while negative values indicate blue tones. Variations in b* values were observed between the samples. The control samples had the lowest b* values, the RSE and RSE-RSME samples had intermediate values, while the RN samples showed the highest values.