## 3 Results and Discussion
### Use of Phenolic Compounds to Inhibit or Block the Maillard Reaction in Bakery Products
#### 3.5.1. Bread
In that study, the quantity of water used in the bread formulation was replaced by PEF. Different substitutions were experimented with 30, 50, and 70 g per 100 g of flour. Experiments showed that the inclusion of the PEF in the bread formulations prevented AGE formation in the glycosylation model systems. In detail, the PEF fraction allowed for the production of bread with higher antioxidative activity and total phenolic content, a lower amount of harmful compounds, and better sensorial quality [32]. Date-seed powder has also been used to enrich pita bread, and the effect of the formulation at different percentages (5, 10, 15, 20%) on acrylamide content was evaluated in [PERSON] et al. [30]. Whatever the degree of date-seed powder enrichment, the level of acrylamide was significantly lower than that in whole-wheat pita bread; the reduction ranged from 50% to 80%, with the 5% addition being the most effective. The inhibitory effect might be related to the fact that the powder is very rich in flavonoids; however, non-linear behavior between the date-seed powder and acrylamide content was found. The highest inhibitory action was, in fact, observed for pita bread enriched at 5% with date-seed powder, and the lowest was found in pita with a 20% addition. Although the reasons for this trend are not fully understood, it is possible that the increase in fat content resultedin a higher proportion of carbonyl groups that were likely to react with amino acids and, consequently, release acrylamide. Since the mechanisms beyond the inhibitory effect of the addition of phenolic extracts or powders rich in phenolic compounds still remain unclear, because of the chemical diversity of polyphenols and the complexity of their composition in plant foods, the effect of pure phenolic compounds was taken into consideration [33]. [PERSON] et al. added pure standards of gallic acid, ferulic acid, caffeic acid, (+)-catechin, and quercetin to a bread model at different concentrations (0.1%, 0.5%, 1.0%, and 2.0%, \(w/w\)) and investigated their effect in inhibiting acrylamide formation [33]. (+)-Catechin, ferulic acid, gallic acid, and caffeic acid exhibited an inhibitory effect on acrylamide formation at all concentrations, while the addition of quercetin reduced acrylamide content only at the lowest concentration (0.1%). This result might be linked to the fact that in some cases, such as for catechol compounds, high concentrations of phenolic compounds generate hydrogen peroxide, which is actually involved in the formation pathway of acrylamide [33]. Comparing the effects of the different concentrations for each phenolic compound on acrylamide formation, it emerged that gallic acid was most effective when added at 2.0%, ferulic acid at 1.0 and 2.0%, caffeic acid at 2.0%, and (+)-catechin at 0.1% [33]. The effect of the same pure standards (i.e., (+)-catechin, quercetin, gallic acid, ferulic acid, and caffeic acid) on the CML formed by Maillard reaction was also investigated [34]. Inclusion of the phenolic compounds in the bread formulation showed that the rates of CML-formation inhibition ranged from 0.01% to 87.56% in bread crust; this inhibitory effect was dependent on the phenolic compound concentration, but not in a linear manner. Except for ferulic acid, the strongest inhibitory activity of each phenolic compound was exerted at the lowest concentration (0.1%) [34].