## 3 Results and Discussion
### Characterization of Basil Pesto Samples  
#### 3.2.1 Physicochemical and Microbiological Aspects  
The values of pH and moisture content of fresh and pasteurized \"basil pesto\" samples were measured on the production day (1 st day) and during the storage period (7, 15, 30, 60, and 90 days) and the results are shown in Figures 3 and 4. The obtained values of the 1 st day of monitoring showed that the pH (Figure 3) was in the range of 4.81-3.63, where the highest results were detected in F and P samples, which were the ones without the AE. Moreover, statistical differences were observed at different storage times than the corresponding enriched samples (\(p<0.05\)). A general decreasing trend of pH was observed at the beginning of the storage to the successive period, particularly in P samples: this was also observed by [PERSON] and [PERSON] [1], with higher results than those noted by other authors. This difference is probably due to the different chemical characteristics of the raw materials linked to the seasonal and varietal variables. The addition of AE led to natural acidification that was observed in F+ and P+ samples (range of 3.72 and 3.62); therefore, AE can be used as a pH corrector in place of  
Figure 4: Moisture content (mc%) of fresh and pasteurized samples during the storage period. Letters show differences by [PERSON]’s multiple range test (lowercase among the same sample during the storage period and uppercase among the different samples). Figure 3: pH values of fresh and pasteurized samples during the storage period (from 1 to 90 days). Letters show differences by [PERSON]’s multiple range test. citiric acid and/or ascorbic acid. Moisture was significantly (_p_ < 0.01) different in the samples (Figure 4), with the highest content in the F+ sample and a general decrease during the storage time except in P samples which were similar for that qualitative parameter (_p_ > 0.05). The samples showed water activity values from 0.954 at the beginning to 0.970 at the end of storage period with no great differences (data not shown). The color of pesto is an important qualitative parameter for consumer acceptability, especially from a point of view of a first and immediate evaluation. The a* chromatism (representing the greenness color intensity) was used as an index to define the color changes of basil pesto samples because it is the most important parameter used for green vegetable products. Color analysis results are reported in Table 3: the statistical analysis showed significant differences among the samples and among the storage times. The highest intensity of the green color (a*) was in fresh pesto \"F\" (-5.45 \(\pm\) 0.32), whereas the addition of AE slowly reduced this color to \(-\)3.96 \(\pm\) 0.31 in F+ immediately after production. Moreover, the thermal stabilization involved a reduction in this parameter (P: \(-\)1.65 \(\pm\) 0.60 and P: +1.56 \(\pm\) 0.26), which also significantly decreased during the storage period (_p_ < 0.01), particularly in the pasteurized samples. The main attributes responsible for the green color of pesto are chlorophyll pigments and its degradation products. Low pH and high temperatures play a key role in the transformation of chlorophylls into the respective brownish products of pheophytins, pheophorbirds, and pyropheophitins [33]. For the overall color change (\(\Delta\)E) evaluation, considering the fresh and pasteurized samples for the previously mentioned initial different results separately, the enriched samples (F+ and P+) showed the lowest color variation with respect to F and P, denoting a better visual quality. Among other qualitative parameters, the overall acceptability and sensorial aspects of the product were assessed, and the results are reported in Figures 5 and 6. The attributes evaluated by the panel were: color (intense green and oxidate green), odor (basil, garlic, cheese, cashews, rancidity, and acidity) and texture.