## 3 Results and Discussion
### Bread Shelf-Life Evaluation  
Black garlic has been found to have higher antibacterial activity than fresh garlic. It exhibits inhibiting activity against the growth of pathogenic bacteria, including _Staphylococcus aureus, Klebsiella pneumoniae, Enterococcus faecalis, Listeria monocytogenes, Escherichia coli,_ and _Pseudomonas aeruginosa_[40; 41]. In particular, Gram-positive bacteria are more sensitive than Gram-negative bacteria to black garlic, while yeasts, including _Saccharomyces cerevisiae,_ are the most resistant microorganisms [42]. Moreover, black garlic melanoidins and protein extract exhibit excellent in vitro \(\alpha\)-amylase and \(\alpha\)- and \(\delta\)-glucosidase inhibition activity, with a dose-dependent relationship between melanoidin and protein extract concentrations and the inhibition rate [43]. According to [PERSON] et al. 2025 [44], our BGP sample showed low solubility and a low WHC (0.86 \(\pm\) 0.04 \(\mathrm{g_{water}/g_{dw}}\)). Suspensions of 1% in water showed a pH of 4.19 \(\pm\) 0.06 and acidity of 1.4 \(\pm\) 0.0. The BGP dissolved in 0.1% peptone solution at the same concentration did not present any microorganism growth in the bread. For the evaluation of the bread's shelf life, the samples were stored in micro-perforated plastic bags designed for food storage for 8 days at room temperature. After 0(t0), 4(t4), and 8(t8) days, the pH, acidity, % of water loss, and water-holding capacity were determined. Moreover, microbiological analyses were performed using the wheat and BGP-added breads at the three storage times. The results obtained are reported in Table 4. Before the analysis, the breads were weighed, and the weight decrease was understood as water loss. The percentage of water loss decreased as a function of the quantity of BGP added, and this trend was particularly evident at the time t8, when the wheat bread lost 20.4% of its water and the bread enriched with 3 g/100 g of BGP lost only 3.4% of its water. The ability of proteins to absorb and retain water against gravity is expressed by the WHC parameter. This parameter plays an important role in the textural quality of baked products. During the storage period, the WHC decreased from t0 to t4 and returned to the initial value at t8 for each sample. Among different breads, the WHC value slightly decreased from the wheat bread to the bread with 2% BGP added, and there was an increment in the bread with 3% of BGP product. Although the latter product demonstrated a minor loss in water content, its textural acceptability was lower because it was judged as too dry). [PERSON] et al. [45] studied the WHC of black garlic protein extract and observed that enzymatic hydrolysis significantly improved the WHC. During hydrolysis, proteins were cleaved into smaller peptide fragments, exposing more hydrophilic groups. The pH of the breads decreased as a function of the quantity of BGP added and showed a slight tendency to decrease over the storage period. The percentage of BGP had a great influence on sensory evaluation; in fact, the addition of 3 g/100 g of BGP reduced the overall acceptability, and the taste was judged as having an acidic aftertaste. According to the pH, the acidity of the bread increased according to the % of BGP added, while no significant change was observed during the storage period, with the exception of the bread prepared with 3 g of BGP, for which the acidity increased from t\({}_{0}\) to t\({}_{8}\). A microbiological analysis (Table 5) of the wheat bread and bread with black garlic powder prior to storage showed that the initial total microorganism levels were below 10 cfu/g (t\({}_{0}\)). At this time, the wheat bread and bread with different powder concentrations added did not contain any microorganisms, and throughout storage at 20 \({}^{\circ}\)C for 5 days, no microbiological modifications were observed.