## 3 Results and Discussion
### Chicken Nugget Shelf Life  
To assess the product shelf life, microbiological quality, pH and sensory properties were monitored during about two weeks of storage at 4 \({}^{\circ}\)C.  
As regards the evolution of spoilage microorganisms, Figure 1 reports a trend of the experimental data of mesophilic bacteria recorded in our samples. As can be observed in the figure, total mesophilic counts in the two control samples grew rapidly and overlapped the microbial threshold within the first 3 days of storage. On the other hand, in the same figure it can be observed that the other four treated samples recorded a different microbial evolution, with growth rate more delayed and lag phase more prolonged, if compared with those of the control meat. To better highlight differences among samples, a fitting procedure was adopted, and the MAL value was calculated for each specific microbial specie, as main fitting parameter. In Table 4 are listed the MAL values recorded for the mesophilic bacteria. As can be seen, the first column of Table 4 reports statistically significant different (\(p<0.05\)) values among tested samples. In particular, it is worth noting that low values around 2 days were recorded for both the control nuggets, whereas MAL around 7, 8 and 9 days were calculated, depending on the combination of GPP with LA, PE or both, respectively. The effects are not surprising considering the well-known properties of these active agents, as assessed from data reported in Table 3. Literature on grape pomace applied as breading to meat products is not abundant but much information is available on extracts from grape pomace and grape seeds applied to raw and cooked beef, pork and chicken meat, with interesting effects on microbial proliferation and antioxidant activity. Though environmental and agricultural factors can influence the composition of grape extracts, microorganism numbers generally decreased in proportion to extract concentration [33; 34]. The use of pomerangate by-products as a source of natural antioxidant and antimicrobial compounds in processed meat products has been also investigated and the effects on microbial growth have been abundantly demonstrated [35]. [PERSON] et al. [36] enhanced the shelf life of chicken meat products by 2-3 weeks during chilled storage with pomerangate peel extract. They found that pomerangate seed extract did not have any  
Figure 1: Evolution of total mesophilic bacteria in controls and treated meat samples during storage at 4 \({}^{\circ}\)C. \(\bullet\)CTRL\(\_1\); \(\bullet\)CTRL\(\_2\); \(\blacksquare\) Samp\(\_1\); \(\blacksquare\) Samp\(\_2\); \(\blacksquare\) Samp\(\_3\); \(\blacksquare\) Samp\(\_4\). The curves are the best fit to the experimental data. \(\bullet\)CTRL\(\_1\); \(\bullet\)CTRL\(\_2\); \(\blacksquare\) Samp\(\_1\); \(\blacksquare\) Samp\(\_2\); \(\blacksquare\) Samp\(\_3\); \(\blacksquare\) Samp\(\_4\). The dotted line represents the threshold for acceptability (10\({}^{\circ}\) cfu/g). significant activity, while pomegranate peel extract showed excellent antioxidant potential, good reducing power and iron chelation capacity and good antimicrobial activity. As regards _Pseudomonas_ spp., Figure 2 reports trends in the data. In this figure it is notable that the two control samples grew in a few hours from the day of production and packaging, whereas the other four samples present different microbial evolutions. In particular, microbial growth was more delayed for the nuggets where GPP was combined with LA (Samp_2) and where GPP was combined with LA and PE (Samp_4). These data trends report an important lag phase and Samp_4 in particular maintained a very low bacterial count for the entire observation period. In Table 4 the calculated MAL values for _Pseudomonas_ spp. can be found. Compared with the control meat, the other samples recorded higher values, though the two best antimicrobial solutions were found with Samp_2 and Samp_4. This result can be ascribed to the effects of LA, which acts in