## 2 Results and Discussion
### Multivariate Analyses of Metabolites in the Five Rice Varieties
\begin{table}
\begin{tabular}{l c c c} \hline \hline
**Differential Metabolites** & **RT [min]** & \(p\)**-Value** & **VIP** \\ \hline MEI vs. DAO & & & \\ Butyl benzoate & 27.34 & \(2.51\times 10^{-9}\) & 4.71 \\
2,2-Dichloroethanol & 21.64 & \(1.79\times 10^{-11}\) & 4.57 \\ Sulfurons acid dodecyl pentyl ester & 16.81 & \(0.000306\) & 3.57 \\
2,6,7-Trimethyldecane & 6.03 & \(0.088075\) & 3.54 \\
2-Acetyl-1-pyrroline & 14.64 & \(1.66\times 10^{-9}\) & 3.46 \\
1-3-Dichloro-2-methylbenzene & 19.75 & \(3.05\times 10^{-7}\) & 3.22 \\ (Z)-2-Octen-1-ol & 21.96 & \(1.29\times 10^{-6}\) & 3.03 \\
4,8-Dimethylundecane & 10.76 & \(0.122349\) & 3.02 \\
2,4,6-Trimethylpyridine & 15.71 & \(2.17\times 10^{-7}\) & 2.87 \\
2-Bromocycloheptanone & 17.66 & \(1.40\times 10^{-6}\) & 2.86 \\ DL-2-Phenyl-1,2-propanediol & 25.13 & \(2.44\times 10^{-7}\) & 2.69 \\
2-(1-Cyclopent-1-enyl-1-methylethyl)cyclopentanone & 25.27 & \(0.006072\) & 2.61 \\
2-(Octyloxy)ethanol- & 7.83 & \(4.70\times 10^{-6}\) & 2.46 \\ Indole & 37.99 & \(0.000225\) & 2.41 \\ Borane-methyl sulfide complex & 2.04 & \(2.04\times 10^{-6}\) & 2.34 \\ Methyl Isobutyl ketone & 5.19 & \(0.001067\) & 2.27 \\ Tetramethylpyrazine & 18.45 & \(0.195585\) & 2.24 \\
1,4-Diethoxybenzene & 28.53 & \(1.73\times 10^{-5}\) & 2.19 \\
6,6-Dimethylcyclohex-2-en-1-ol & 26.87 & \(2.55\times 10^{-6}\) & 2.18 \\ Succinic acid but-3-yn-2-yl 2-methylpent-3-yl ester & 15.49 & \(3.62\times 10^{-6}\) & 2.12 \\
3-Methylpyridine & 13.42 & \(4.53\times 10^{-7}\) & 2.12 \\
2-Ethylphenoic acid & 26.99 & \(0.00476\) & 2.10 \\
1-Ethyl-3-methylbenzene & 11.33 & \(0.000117\) & 2.08 \\
1-(1\(H\)-Pyrrol-2-yl)-ethanoneone & 29.47 & \(3.45\times 10^{-8}\) & 2.05 \\ Dibutoxymethane & 11.28 & \(2.11\times 10^{-5}\) & 2.03 \\
3-Butene-1,2-diol & 8.35 & \(1.59\times 10^{-6}\) & 2.03 \\ Furfurral & 17.95 & \(8.58\times 10^{-5}\) & 2.02 \\
3-B-Dihydroxy-3,4-dihydronaphthalene-1(2\(H\))-one & 38.62 & \(1.33\times 10^{-5}\) & 1.98 \\
4-Methylhexyl isobutyrate & 9.18 & \(6.59\times 10^{-6}\) & 1.97 \\ MEI vs. HU & & & \\
2-Methyloctylbenzene & 6.37 & \(0.003302\) & 6.53 \\
2,6,7-Trimethyldecane & 6.03 & \(0.030641\) & 5.37 \\
2,2-Dichloroethanol & 21.64 & \(9.68\times 10^{-5}\) & 4.44 \\
2-Butyl-2-octenal & 23.12 & \(5.16\times 10^{-6}\) & 4.15 \\ Indole & 37.99 & \(7.70\times 10^{-7}\) & 3.58 \\ Tetramethylpyrazine & 18.45 & \(0.017066\) & 3.52 \\
2-Isopropyl-5-methyl-9-methylenebicyclo[4.4.0]dec-1-ene & 21.43 & \(0.056959\) & 3.49 \\ _trans_-Verbenyl caprate & 14.35 & \(0.01666\) & 3.31 \\ Carbon monoxide & 2.25 & \(0.023602\) & 3.14 \\
1,2-Dimethoxybenzene & 24.32 & \(6.56\times 10^{-6}\) & 3.03 \\ (1S-_exo_)-2-Methyl-3-methylene-2-(4-methyl-3-pentenyl)bicyclo[2.2.1]heptane & 22.69 & \(1.43\times 10^{-5}\) & 2.99 \\
1,3-Dimethoxybenzene & 24.80 & \(2.90\times 10^{-8}\) & 2.76 \\ Acetio & 13.11 & \(3.12\times 10^{-5}\) & 2.76 \\
2,4,6-Trimethylpyridine & 15.71 & \(2.17\times 10^{-7}\) & 2.40 \\ (E)-2-Hexenal & 11.16 & \(0.002133\) & 2.28 \\
1-Ethyl-3-methylbenzene & 11.33 & \(5.30\times 10^{-5}\) & 2.26 \\
1-Ethenylaziridine & 5.45 & \(1.55\times 10^{-5}\) & 2.25 \\ _trans_-2-(2-propyloxy)cyclopentanol & 24.23 & \(0.001288\) & 2.16 \\
6,10,14-Trimethyl-pentadecan-2-ol & 26.30 & \(2.04\times 10^{-5}\) & 2.15 \\ Acetic acid & 17.84 & \(0.000139\) & 2.00 \\ Acetic acid butyl ester & 6.97 & \(3.34\times 10^{-5}\) & 1.98 \\ (Z)-2-Octen-1-ol, & 21.96 & \(0.001148\) & 1.97 \\
3-Nonen-2-one & 19.32 & \(0.044049\) & 1.95 \\ Pentanal & 4.54 & \(0.00045\) & 1.90 \\
1-Ethyl-4-methylbenzene & 13.05 & \(0.000112\) & 1.87 \\ Propanoic acid butyl ester & 8.96 & \(5.78\times 10^{-5}\) & 1.87 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Selected differential metabolites across all pairwise comparisons.