## 2 Results and Discussion
### Multivariate Analyses of Metabolites in the Five Rice Varieties
\begin{table}
\begin{tabular}{l c c c} \hline
**Differential Metabolites** & **RT [min]** & \(p\)**-Value** & **VIP** \\ \hline
2-Bromocyclheptanone & 17.66 & 0.000474 & 2.55 \\
2-Methyl-2-propenoic acid 4-formyl-2-methoxyphenyl ester & 13.88 & \(6.99\times 10^{-7}\) & 2.54 \\
4-Ethyl-4\(H\)-1,2,4-triazole & 4.98 & \(1.12\times 10^{-6}\) & 2.51 \\
3,8-Dihydroxy-3,4-dihydronaphthalen-1(2\(H\))-one & 38.62 & \(1.33\times 10^{-5}\) & 2.49 \\
1-(1\(H\)-Pyrrol-2-yl)ethanone & 29.47 & \(2.00\times 10^{-7}\) & 2.43 \\
2-Cyclohexylpiperidine & 23.57 & 0.000698 & 2.40 \\
4,8-Dimethylnona-3,8-dien-2-one & 22.76 & \(6.88\times 10^{-6}\) & 2.34 \\
4-_tert_-Butoxysstyrene & 37.17 & 0.000971 & 2.31 \\ Methyl1 8,11,14,17-eicosatetraenoate & 24.46 & 0.005069 & 2.26 \\ N-(1,-1,Dimethyl-prop-2-ynyl)-acetamide & 18.00 & 0.025511 & 2.22 \\ Butanal & 2.88 & 0.016879 & 2.21 \\
2-Methyloctyl)benzene & 6.37 & 0.372951 & 2.21 \\
1-_sec_-Butyl-3-nitro-4-amino-1,2,5-triazole 2-oxide & 13.53 & 0.038085 & 2.20 \\ Benzaldehyde & 19.44 & 0.000244 & 2.09 \\ YE vs. HU & 21.43 & 0.04846 & 5.67 \\
2-Isopropyl-5-methyl-9-methylenebicyclo[4.4.0]dec-1-ene & 14.35 & 0.021689 & 4.56 \\
2,6,7-Trimethyldecane & 6.03 & 0.253466 & 4.02 \\ Dibutorsystemene & 11.28 & \(2.49\times 10^{-5}\) & 3.84 \\
1,3-Dimethoxybenzene & 24.80 & 0.000178 & 3.79 \\ (\(E\))-2-Hexenal & 11.16 & 0.002022 & 3.51 \\
1,2-Dimethoxybenzene & 24.32 & \(8.75\times 10^{-7}\) & 3.25 \\
1,5-Dimethyl-2-oxabicyclo[3.2.1]nonan-7-one & 13.91 & \(7.20\times 10^{-7}\) & 3.07 \\
4-Chlorophenol & 37.88 & \(7.32\times 10^{-7}\) & 2.85 \\ Hentiracontane & 18.05 & 0.002675 & 2.84 \\ \(n\)-Butylbenzene & 13.93 & 0.022446 & 2.76 \\
6-Methylhept-4-en-1-yl 2-methylbutanoate & 15.88 & 0.000103 & 2.74 \\
2-Propenoic acid butyl ester & 10.00 & \(1.54\times 10^{-5}\) & 2.70 \\ Acetic acid butyl ester & 6.97 & \(7.49\times 10^{-6}\) & 2.68 \\
5-Chloroguaicaol & 33.81 & 0.000571 & 2.64 \\ Carbon monoxide & 2.25 & 0.234365 & 2.60 \\
2-Ethyl-2-(hydroxymethyl)-1,3-propanediol & 14.11 & 0.000948 & 2.53 \\
2-Ethylfuran & 4.03 & \(7.34\times 10^{-6}\) & 2.50 \\ \(n\)-Butyl ether & 4.35 & \(3.31\times 10^{-6}\) & 2.44 \\ Furan, 2-methyl- & 23.33 & \(3.64\times 10^{-7}\) & 2.43 \\
1-Ethyl-4-methylbenzene & 13.05 & \(7.33\times 10^{-6}\) & 2.43 \\
3-Butylpyridine-1-oxide & 20.20 & \(3.01\times 10^{-7}\) & 2.36 \\
4,8-Dimethylundecane & 10.76 & 0.522126 & 2.35 \\ (\(E\))-4-Oxohex-2-enol & 24.96 & 0.000801 & 2.33 \\ Methyl 8,11,14,17-eicosatetraenoate & 24.46 & 0.005068 & 2.32 \\ (\(R\))-(-)-2-Pentanol & 8.62 & 0.01173 & 2.29 \\
1-(3,3-Dimethyloxiranyl)ethanone & 13.61 & 0.010545 & 2.23 \\ N,N,2,2-Tetramethyl-1,3-propanediamine & 1.86 & 0.07517 & 2.19 \\
4-Methylundecane & 9.39 & 0.010168 & 2.18 \\ _cis_-2-(2-Pentenyl)furan & 13.68 & \(2.03\times 10^{-6}\) & 2.17 \\ YE vs. MEI & & & \\ (2-Methyloctyl)benzene & 6.37 & 0.01419 & 8.07 \\
2-2-Dichloroethanol & 21.64 & \(8.96\times 10^{-11}\) & 5.78 \\
2-Butyl-2-Octenal & 23.12 & 0.000407 & 4.95 \\ Indole & 37.99 & \(4.57\times 10^{-5}\) & 4.25 \\
2,6,7-Trimethyldecane & 6.03 & 0.104491 & 3.76 \\ Tetramethylpyrazine & 18.45 & 0.087738 & 3.46 \\ _trans_-2-(2-Propynyloxy)cyclopentanol & 24.23 & \(6.94\times 10^{-5}\) & 3.38 \\
2,4,6-Trimethylpyridine & 15.71 & \(2.17\times 10^{-7}\) & 3.17 \\
22,96 & \(1.18\times 10^{-8}\) & 2.66 \\ \hline \end{tabular}
\end{table} 
Table 2: _Cont._