## 2 Results and Discussion
** & **RT (min)** & **Name** & **RI** & **EDT \({}^{\text{a}}\)** & **EDN \({}^{\text{b}}\)** & **SZT \({}^{\text{c}}\)** & **SZS \({}^{\text{d}}\)** \\ \hline
23 & 7.35 & Cineole & 1020 & 0.25 \(\pm\) 0.09 & 0.60 \(\pm\) 0.06 & 0.03 \(\pm\) 0.02 & 0.21 \(\pm\) 0.03 \\
24 & 9.15 & Estragole & 1188 & 35.45 \(\pm\) 1.17 \({}^{\text{c}}\)d & 28.97 \(\pm\) 4.26 \({}^{\text{c},\text{d}}\) & 2.84 \(\pm\) 0.97 \({}^{\text{a,b}}\) & 9.10 \(\pm\) 2.45 \({}^{\text{a,b}}\) \\
25 & 9.42 & \(O\)-Methylthymol & 1222 & 0.01 \(\pm\) 0.00 & 0.51 \(\pm\) 0.40 & - & - \\
26 & 10.02 & Anethole & 1277 & 17.43 \(\pm\) 1.99 & 7.51 \(\pm\) 1.94 & 13.64 \(\pm\) 0.10 & 25.40 \(\pm\) 14.22 \\  & **Ethers** & **Total** & **53.14** & **37.60** & **16.51** & **34.71** \\ \hline
27 & 4.69 & Furfural & 777 & 0.01 \(\pm\) 0.02 & 0.13 \(\pm\) 0.10 & 0.54 \(\pm\) 0.07 & 0.52 \(\pm\) 0.03 \\
28 & 6.71 & 5-Methyl-2- & 942 & 1.62 \(\pm\) 0.08 & 3.07 \(\pm\) 0.42 & 1.67 \(\pm\) 0.16 & 0.89 \(\pm\) 0.04 \\
29 & 7.64 & Furaneol & 1043 & 0.04 \(\pm\) 0.01 & 0.07 \(\pm\) 0.04 & 0.36 \(\pm\) 0.08 & 0.12 \(\pm\) 0.03 \\
30 & 7.83 & 5-formylfurfurral & 1065 & 0.37 \(\pm\) 0.00 & 2.11 \(\pm\) 1.13 & 0.12 \(\pm\) 0.02 & 0.13 \(\pm\) 0.03 \\
31 & 9.38 & 5-Hydrooxymethylfurral & 1211 & 0.44 \(\pm\) 0.18 & 4.59 \(\pm\) 3.86 & 0.08 \(\pm\) 0.04 & 0.12 \(\pm\) 0.02 \\  & **Furans** & **Total** & **2.48** & **9.96** & **2.76** & **1.78** \\ \hline  
(\alpha\)-Aminoxpropionic acid & 1056 & 0.04 \(\pm\) 0.06 & 0.07 \(\pm\) 0.08 & 0.08 \(\pm\) 0.00 & 0.03 \(\pm\) 0.03 \\  & **Nitrogen-containing compounds** & **Total** & **0.16** &against _P. fluorescens_[15]. Linalool and terpineol were effective against several tested organisms except _Pseudomonas aeruginosa_[16]. Aldehydes (3.5-10.24%): Aldehydes are commonly identified compounds in the aroma of thyme containing mixtures, and a significant aldehyde increase is observed in most volatiles after the addition of thyme [17]. Aldehydes and their derivatives demonstrated considerable antibacterial activity by mechanically destroying bacterial cell membranes [18]. Cuminaldehyde (0.04-1.94%), one of the major aldehydes in cumin [19], improved antibacterial and anti-biofilm properties in _S. aureus_ and _E. coli_ when used in conjunction with ciprofloxacin [20]. Anisaldehyde (0.23-7.51%) reported in sumac [21] synergistically improved nisin antimicrobial activity against several resistant food borne pathogens [22]. Esters (0.21-3.3%): Esters are considered to be one of the most important biologically active ingredients in different essential oils compositions [23]. Five esters were found in the four herbal mixes under investigation. Ethers (16.51-53.14%): Anethole was one of the major identified ethers (7.51-25.40%) that was previously reported as a volatile oil component in thyme [13; 24] and was detected as a major constituent in coriander [25]. Anethole-rich volatile oils exerted significant antioxidant and antimicrobial activities [26]. Ketones (1.16-17.38%): Ketones were most abundant in nut-based and thyme-based Egyptian dukkah and were represented by carvone (1.06-14.83%) as the major form. It exceeded 14% of the total volatiles in nut-based Egyptian dukkah. Carvone is the major component of the volatile oil of the family Lamiaceae (including thyme) [27] and was identified as a component of coriander volatile oil [28]. Carvone was proposed to be the most responsible for mentha antibacterial activity against various foodborne pathogenic bacteria [29]. A previous study on 12 fennel accessions demonstrated that anethole and estragole were the main volatiles present at various combinations reaching maximum abundance at 98.4% and 72.4%, respectively. Subsp. pipertium from Minia, Egypt had the highest average estragole exposure at ca. 35 mg/kg body weight for 5 g fennel consumption per day, warranting cautious use in sensitive groups, i.e., nursing mothers and infants [13]. However, our findings indicated much lower estragole level (2.84-35.45%), suggestive of the safe daily use of dukkah and za'atar for prolonged periods.