# Evaluation of the Nutritional Quality and Shelf Life of
## 4 Discussion
### Lactic Acid Bacteria Growth Analyses over Shelf Life  
Before maturation, after the filling process, the salami had a count higher than \(10^{7}\) CFU/g which allowed them to be considered probiotics and continue the fermentation and maturation processes. After those stages, the growth of _Lactobacillus casei_ increased considerably, results similar to those found in another study with _L. casei_-inoculated salami [36], and that of _Lactobacillus paracasei_ diminished, indicating that it did not multiply significantly during fermentation; however, some viable cells were still found. Over their growth time, both strains had noticeable growth from the bacterial count, showing that storage and the absence of curing salts did not influence the evolution of these _Lactobacillus_ negatively. The decay of these bacteria started on day 56 of storage, although viable strains were maintained above \(10^{7}\) CFU/g even after that time, which reveals that the product is viable for 84 days, guaranteeing a functional probiotic product during its shelf life. The viable cell count in the probiotics with _L. casei_ and _L. paracasei_ increased gradually post-maturation and after the first 14 days, exhibiting their activity over that time in viable quantities. In the first 14 days, the samples showed a count of \(10^{7}\) and \(10^{10}\) CFU/g for _L. casei_ and _L. paracasei_, respectively, during the lag phase, when bacteria are still adapting to the new environment and their growth is mostly affected by pH and acidity over the processed food's shelf life. In days 28 through 42 the greatest population growths were observed for both the processed meats, reaching a count in order of \(10^{15}\) and \(10^{13}\) CFU/g for _L. casei_ and _L. paracasei_, respectively, which happened because of the increase in present cells during the lag or exponential phase, when the strains have greater growth in the medium. However, a reduction in that was observed in the samples after 70 days of storage, getting to the stabilization and decline phase with 1.82 \(\times\) 10\({}^{7}\) and 6.8 \(\times\) 10\({}^{7}\) CFU/g, when the probiotics stopped growing and started the cell death stage. These results over storage periods showed that the most active viable cells are found between the 14 th and 70 th day of storage. That fact is noticeable when the parameters of acidity, pH, humidity, and water activity are evaluated to help the population growth of the microbial _Lactobacillus_ strains over storage time, especially during the first 28 days [37]. The survival of probiotic bacteria in fermented products depends on many factors, like the interaction between the species found in the food, culture conditions, chemical composition of the medium, final acidity of the product, salt content, nutrient availability, growth promoters and inhibitors, dissolved oxygen, the amount of probiotic inoculate, incubation time, and storage temperature [38]. Even with the pH variation, _Lactobacillus_ developed over time. When we compare the results of this research with other studies in the literature, we found that processed meat with the addition of _Lactobacillus acidophilus_ at the end of maturation had values of \(10^{8}\) CFU/g and, after 90 days of storage, the formulations show a decrease in the population of _Lactobacillus_ spp. [29]. Another study assessed the growth of _L. casei_ in salami and also obtained values of \(10^{8}\) CFU/g for viable cells [37]. A population of \(10^{7}\) CFU/g viable cellswas found in research with _L. paracasei_ in fermented processed meat with reduction in nitrate and nitrite at the end of the storage period. All those studies showed similar results to the ones found at the end of the storage period in the current study [1]. The values observed confirmed a resistance to pH and humidity changes and indicate that the strains used in fermentation are capable of surviving and multiplying in the meat used.