## 3 Results and Discussion
### TPC, TFC, and Antioxidant Activity of SWAP and Fortified Wheat Breads  
The TPC and TFC of free phenolic extracts of ORE, ROS, LEB, and SPE post-distillation solid wastes varied from 33.30 to 65.36 mg GAE/g and 23.17 to 49.13 mg CATE/g, respectively (Figure 6a), with LEB exhibiting the highest TPC and TFC values. Regarding TFC, the rest of the post-distillation solid wastes did not differ significantly (\(p>0.05\)) among them, whereas the TPC values decreased in the following order: LEB > ROS > ORE > SPE. This ranking remained the same for the DPPH values, while the ABTS and FRAP values showed a slightly different trend; among the post-distillation waste residues tested, with all three used assays, the LEB sample showed the highest antioxidant capacity (Figure 6b). The levels of TPC and TFC values significantly correlated with the antioxidant capacity as evaluated using the ABTS, DPPH, and FRAP assays, as evidenced by the high correlation coefficients of 0.840, 0.971, 0.957, and 0.641, 0.924, 0.962, respectively (\(p<0.01\)). These coefficients reveal the high degree of association of phenolic and flavonoid content with the antioxidant capacity and the potential that these materials could have in improving the antioxidant status of food products fortified with these residues. In general, solid wastes obtained from the distillation of MAPs of the Lamiaceae family are reported to have high TPC, TFC, and antioxidant activity [11], with lemon balm exhibiting similar values to that of spearmint but higher than oregano, sage, rosmears, and satureja. In their study, [PERSON] et al. [39] reported that by-products from the hydro-distillation of _Origanum vulgare_ along with _Melissa officinalis_ showed the highest TPC compared to the other plants of the Lamiaceae family (_Salvia officinalis L., Mentha piperta L., Thymus vulgaris_ L., and _Hyssopus officinalis_ L.). Similarly, [PERSON] and [PERSON] [40] have reported that oregano and thyme showed the highest contents of phenolics followed by melissa and rosmears. Differences in the amount of phenolics and the antioxidant capacity found could be not only due to the plant type, but also the result of different distillation, drying and extraction methods that can affect the remaining phenolics in the plant residues. It is obvious that breads supplemented with SWAP material had significantly higher free and total TPC, TFC, and antioxidant capacity than the control bread (Table 2). Thus, it seemed that these functional breads fortified with SWAP had improved antioxidant properties, especially in the formulations made with a higher supplementation level (2%). Figure 6: Total phenolic (TPC) and total flavonoid (TFC) contents (**a**) and antioxidant activity evaluated using ABTS, DPPH, and FRAP assays (**b**) of the post-distillation solid waste residues of oregano (ORE), rosmears (ROS), lemon balm (LEB) and spearmint (SPE); GAE: gallic acid equivalents were used for expressing TPC content; CATE: chatechin equivalents were used for expressing triC content; TE: Trolox equivalents were used for expressing antioxidant capacity, as evaluated by the ABTS, DPPH and FRAP assays; mean values for the same parameter with different letter are significantly different (Tukey’s test, \(p<0.05\)). In general, the bread supplemented with LEB residue contained the highest amount of TPC, TFC, and antioxidant capacity among all tested breads, which is in agreement with the findings for the respective parameters of the SWAP raw materials of breads (Figure 6), whereas the ORE breads exhibited the lowest values (Table 2). Additionally, it seemed that free TPC in bread samples represented 22.1 to 49.0% of the total TPC, while free TPC corresponded to 38.4 to 77.5% of the total TFC, suggesting that most of the TPC in breads are present in a bound form.