## 3 Results and Discussion
### Aroma Recombination and Omission Studies of the Non-Smoked Bacon
This provides effective molecular information for the quality evaluation and geographic differentiation of non-smoked bacon. The variations in the aroma of non-smoked bacon primarily resulted from the quantity of different volatiles, while the differences in the categories of volatile compounds were trivial. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Compounds** & **Quantitative Ions a** & **Standard Curves b** & **R2** \\ \hline Hexanal & 44, 56, 72, 27 & y = 0.2735x + 0.1596 & 0.9932 \\ Nonanal & 57, 41, 43, 56 & y = 0.4929x \(-\) 0.1045 & 0.9979 \\ Heptanal & 44, 27, 55, 70 & y = 0.2328x \(-\) 0.2125 & 0.9968 \\ Decanal & 56, 55, 41, 43 & y = 0.9334x \(-\) 0.2805 & 0.9861 \\ Octanal & 43, 44, 41, 56 & y = 0.1527x \(-\) 0.7610 & 0.9968 \\ (E)-2-Nonenal & 41, 43, 29, 55 & y = 0.3585x + 0.1831 & 0.9978 \\ (E,E)-2,4-Decadienal & 81, 41, 29, 39 & y = 0.3159x + 0.1903 & 0.9956 \\
2-Undecenal & 70, 41, 57, 43 & y = 0.3336x + 0.1133 & 0.9975 \\
1-Octen-3-ol & 57, 43, 72, 29 & y = 0.3077x + 0.2273 & 0.9974 \\
1-Hexanol & 56, 43, 41, 39 & y = 0.3201x \(-\) 0.2449 & 0.9969 \\
1-Octanol & 56, 55, 41, 43 & y = 0.6931x \(-\) 0.4813 & 0.9901 \\
2,3-Butanediol & 45, 43, 27, 57 & y = 0.4102x \(-\) 0.1892 & 0.9924 \\
2,3-Octanedione & 43, 30, 41, 27 & y = 0.1776x \(-\) 0.3727 & 0.9971 \\ Butyldihydro-2(3H)-furanone & 85, 29, 56, 41 & y = 0.5138x \(-\) 0.2752 & 0.9858 \\ Dihydro-5-pentyl-2(3H)-furanone & 85, 29, 41, 43 & y = 0.4636x + 0.1317 & 0.9988 \\
5-Ethyldihydro-2(3H)-furanone & 85, 29, 56, 57 & y = 0.2432x \(-\) 0.1592 & 0.9986 \\
3-Methyl-butanoic acid & 60, 43, 41, 45 & y = 0.1087x \(-\) 0.3425 & 0.9911 \\ Pentanoic acid & 60, 73, 41, 45 & y = 0.8277x \(-\) 0.2338 & 0.9878 \\ Hexanoic acid & 60, 73, 41, 43 & y = 0.6026x \(-\) 0.8420 & 0.9759 \\ Heptanoic acid & 60, 73, 41, 87 & y = 0.2074x + 0.6202 & 0.9972 \\ \hline \hline \end{tabular} a: Monitored ions used for quantitation. b: Variables x and y represent the concentration ratio (the concentration of the standard of volatile compounds/internal standard) and the peak area ratio (the peak area of standard/internal standard).  
\end{table} 
Table 4: Authentic standards, quantitative ions, and standard curves in determination of volatile compounds in selected ion monitoring mode. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**No.** & **Compounds a** & **Correct Number b ** & **Significance c ** \\ \hline \hline Yunnan bacon & & & \\
1 & Hexanal & 12/12 & ** \\
2 & (E)-2-Nonneal & 5/12 & – \\
3 & (E,E)-2-Decalenal & 8/12 & * \\
4 & 1-Octen-3-ol & 12/12 & ** \\
5 & 2,3-Butanediol & 6/12 & – \\
6 & 1-Hexanol & 8/12 & * \\
7 & 2,3-Octenolone & 9/12 & ** \\
8 & 5-Ethydlihydro-2(3H)-furanone & 3/12 & – \\
9 & Dihydro-5-pentyl-2(3H)-furanone & 8/12 & * \\
10 & 3-Methyl-butanoic acid & 10/12 & ** \\
11 & Pentanoic acid & 4/12 & – \\
12 & Hexanoic acid & 9/12 & ** \\ Chongqing bacon & & & \\
1 & Hexanal & 12/12 & ** \\
2 & (E)-2-Nonneal & 9/12 & ** \\
3 & (E,E)-2-Decalenal & 8/12 & * \\
4 & 2-Ducleonal & 9/12 & ** \\
5 & 1-Octen-3-ol & 12/12 & ** \\
6 & 2-3-Octenolone & 10/12 & ** \\
7 & Dihydro-5-pentyl-2(3H)-furanone & 8/12 & * \\
8 & 3-Methyl-butanoic acid & 8/12 & * \\
9 & Heptanoic acid & 6/12 & – \\ Sichuan bacon & Hexanal & 12/12 & ** \\
1 & Octanal & 11/12 & ** \\
2 & Octanal & 11/12 & ** \\
3 & Nonanal & 7/12 & – \\
4 & Decanal & 6/12 & – \\
5 & (E,E)-2-Decalenal & 8/12 & * \\
6 & Heptanal & 5/12 & – \\
7 & 2-Undeeenal & 8/12 & * \\
8 & 1-Octen-3-ol & 12/12 & ** \\
9 & 2,3-Butanediol & 4/12 & – \\
10 & 1-Octanol & 10/12 & ** \\
11 & 5-Ethydlihydro-2(3H)-furanone & 3/12 & – \\
12 & 5-Butyldihydro-2(3H)-furanone & 9/12 & ** \\
13 & 3-Methyl-butanoic acid & 10/12 & ** \\
14 & Hexanoic acid & 9/12 & ** \\
15 & Heptanoic acid & 6/12 & – \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The results of the triangle test via omission experiments. Figure 4: Aroma profiles of non-smoked bacon compared with aroma recombination model. (**a**) Recombination model of XW bacon; (**b**) Recombination model of ZZ bacon; (**c**) Recombination model of MN bacon.