## 3 Results and Discussion
### Profiles of VOCs
\begin{table}
\begin{tabular}{c c c c c} \hline
**Compound** & **RI** & **Steaming** & **Baking** & **Microwaving** \\ \hline Acids (6) & & & & \\ Acetic acid & 1449 & Nd & 9.11 \(\pm\) 0.21 & Nd \\ Butanoic acid & 1625 & 6.45 \(\pm\) 0.65 ab & 8.09 \(\pm\) 0.49 a & 5.85 \(\pm\) 0.25 b \\ Hexanoic acid & 1842 & 3.92 \(\pm\) 0.36 ab & 5.15 \(\pm\) 0.78 a & 3.31 \(\pm\) 0.23 b \\ Octanoic acid & 2054 & 2.74 \(\pm\) 0.09 b & 5.06 \(\pm\) 0.25 a & 2.59 \(\pm\) 0.14 b \\ Nonanoic acid & 2155 & 61.62 \(\pm\) 3.72 b & 85.15 \(\pm\) 4.34 a & 12.62 \(\pm\) 1.48 c \\ Decanoic acid & 2271 & 4.15 \(\pm\) 0.18 & 6.62 \(\pm\) 0.26 & Nd \\ Alcohols (3) & & & & \\
6-Methyl-1-heptanol & 1226 & Nd & 3.43 \(\pm\) 0.09 & Nd \\
1-Octen-3-ol & 1450 & 10.85 \(\pm\) 0.62 & 14.19 \(\pm\) 1.36 & Nd \\
1-Octenol & 1557 & Nd & 2.22 \(\pm\) 0.17 & Nd \\ Aldehydes (15) & & & & \\ Pentanal & 969 & Nd & Nd & 47.92 \(\pm\) 2.41 \\ Hexanal & 1081 & 60.55 \(\pm\) 2.85 a & 37.75 \(\pm\) 1.34 b & 35.86 \(\pm\) 1.19 b \\
3-Methyl-hexanal & 1183 & 1.05 \(\pm\) 0.28 & Nd & Nd \\ Heptanal & 1188 & Nd & Nd & 10.18 \(\pm\) 0.28 \\ Octanal & 1287 & 6.74 \(\pm\) 0.19 c & 10.49 \(\pm\) 0.45 b & 15.65 \(\pm\) 0.63 a \\ Nonanal & 1392 & 27.36 \(\pm\) 1.84 c & 45.11 \(\pm\) 2.80 b & 66.48 \(\pm\) 2.40 a \\ (_E_)-2-Octenal & 1413 & 9.24 \(\pm\) 0.41 a & 8.86 \(\pm\) 0.23 a & 4.25 \(\pm\) 0.12 b \\ Decanal & 1495 & 3.72 \(\pm\) 0.07 & 3.82 \(\pm\) 0.16 & 3.57 \(\pm\) 0.06 \\ Benzaldehyde & 1518 & 12.24 \(\pm\) 0.24 c & 35.86 \(\pm\) 2.61 b & 61.87 \(\pm\) 3.71 a \\ Benzaceaealdehyde & 1631 & 4.87 \(\pm\) 0.08 b & 14.13 \(\pm\) 0.63 a & 15.86 \(\pm\) 0.57 a \\ (_Z_)-2-Decneal & 1640 & 2.54 \(\pm\) 0.14 & Nd & Nd \\
2-Undecneal & 1712 & 2.45 \(\pm\) 0.12 & 2.59 \(\pm\) 0.11 & Nd \\ (_E,E_)-2,4-Decadienal & 2143 & 2.55 \(\pm\) 0.10 & 2.76 \(\pm\) 0.26 & 2.54 \(\pm\) 0.19 \\ Hexadecanal & 2149 & 6.57 \(\pm\) 0.17 b & 10.16 \(\pm\) 0.30 a & 10.93 \(\pm\) 0.62 a \\ Pentadecanal & 2242 & Nd & 2.41 \(\pm\) 0.12 & 2.43 \(\pm\) 0.14 \\ Alkanes (6) & & & & \\
3-Methyl-undecane & 1154 & 10.29 \(\pm\) 0.26 & Nd & Nd \\
2,2-Dimethyl-butane & 1205 & Nd & 7.50 \(\pm\) 0.14 & Nd \\ Dodecane & 1201 & 10.41 \(\pm\) 0.31 & Nd & Nd \\ Tridecane & 1302 & 8.83 \(\pm\) 0.21 & 7.38 \(\pm\) 0.19 & Nd \\
3-Methyl-triadecane & 1369 & 4.91 \(\pm\) 0.05 & Nd & Nd \\ Tetradecane & 1403 & 6.48 \(\pm\) 0.14 & Nd & Nd \\ Esters (2) & & & & \\
1,2-Benzenedicarboxylic acid, & 2590 & 50.34 \(\pm\) 1.17 b & 60.59 \(\pm\) 2.75 a & 7.76 \(\pm\) 0.33 c \\ bis(2-methyl propyl) ester & & & & \\ Dibutyl phthalate & 2684 & 75.32 \(\pm\) 2.14 a & 50.42 \(\pm\) 1.81 b & 4.73 \(\pm\) 0.15 c \\ Furans (1) & & & & \\
2-pentyl-furan & 1236 & 25.55 \(\pm\) 0.57 & Nd & Nd \\ Ketones (1) & & & & \\
1-Hepten-3-one & 1307 & Nd & Nd & 5.09 \(\pm\) 0.22 \\ Pyrazines (9) & & & & \\ Pyrazine & 1211 & Nd & 2.49 \(\pm\) 0.10 & Nd \\
2,5-Dimethyl-pyrazine & 1315 & Nd & 45.27 \(\pm\) 2.02 & 99.73 \(\pm\) 3.99 \\ \hline \end{tabular}
\end{table} 
Table 3: Relative content (ng/g) of VOCs according to the different cooking methods of SEY. The microwave-treated SEY had significantly higher fractions of pyrazines compared to the baking group, while pyrazine fractions were absent in the steaming group. Pyrazine was recognized as one of the primary products of the Maillard reaction, formed by the Strecker degradation of leucine, isoleucine, and glycine, possessing robust sensory attributes [42]. A recent study demonstrated that the content of pyrazine accumulated along with the fermentation process, which ultimately affected the burnt, nutty/cocoa aroma of the food and was also a key aroma substance in SEY [43]. Notably, 2.5-dimethyl-pyrazine had a distinctive baking aroma reminiscent of roasted peanuts/potatoes and played a prominent role in both microwaving and baking treatments. Only trace amounts of ketones were found in the microwaving group. As reported previously, ketones were not typically present in fresh eggs and may arise from secondary reactions involving carboxylic acids during processing [44].