## 3 Results and Discussion  
### Shelf-Life Study  
#### 3.1.1 Microbial Growth  
In this section, the experimental results of the examined bacon samples and mathematical modeling of isothermal microbial growth (lag, exponential, stationary phases) of two different examined microbial groups, (i) aerobic plate count (APC) and (ii) lactic acid bacteria (LAB), are presented. The number of microorganisms (pathogens and/or spoilage microorganisms) present in foods influences the safety and quality of the food product. Predicting and modeling the number of microorganisms and the rate of microbial growth under specific storage conditions can help to understand and predict food safety risk assessments [33]. Accurately estimating the number of microorganisms present during the \"lifetime\" of food before consumption requires a quantitative knowledge of the microbial responses to environmental conditions (temperature, nutrients, chemicals, preservatives, other microorganisms), synthesized in a mathematical model, which enables objective evaluation of the effects of processing, distribution, and storage conditions on the safety and quality of food [34]. A mathematical model that quantitatively describes the combined effect of these environmental parameters can be used to predict the growth, survival, or inactivation of a microorganism, thereby providing important information on the product's safety and shelf-life [29; 30]. The growth data for aerobic plate count (APC) and lactic acid bacteria (LAB) in the four different categories of bacon samples examined were fitted using a two-step modeling approach and statistical analysis based on SSE results between the experimental data and the model-predicted data. For the case of the APC of the bacon samples, the microbial growth data observed from the bacon samples without any added antimicrobial factors (reduced nitrite (RN) samples) presented the highest rates of microbial growth at all three different temperatures tested, with values of \(\mu_{\text{max}}\) of 0.283 d\({}^{-1}\) and 0.666 d\({}^{-1}\) at 5 \({}^{\circ}\)C and 15 \({}^{\circ}\)C, respectively. On the other hand, the antimicrobial effect of the rose extract appeared to be more effective for APC growth, with the RSE samples presenting the lowest APC microbial growth rate, with values of 0.163 d\({}^{-1}\) and 0.599 d\({}^{-1}\) at 5 \({}^{\circ}\)C and 15 \({}^{\circ}\)C, respectively (Figure 1). The combined incorporation of rose and rosemary extracts in the RSE-RSME samples showed a better antimicrobial performance when compared to the RN samples, but did not show any further beneficial effect to microbial inhibition when comparing these results to the traditionally produced counterparts. To be more specific, conventionally produced samples (CNT control samples), containing the maximum nitrite content allowed by legislation, appeared to have an effective antimicrobial impact (as anticipated) similar to that of the RSE samples at higher temperatures (10 and 15 \({}^{\circ}\)C). Nonetheless, it is worth noting that at the lower temperature of 5 \({}^{\circ}\)C (representative of the chilled conditions of the cold storage of this product), the RSE samples, with half the nitrite content, seemed to inhibit microbial growth more effectively when compared to their CNT counterparts.