## 3 Results and Discussion
### Comparison of Analyte Profiles from Different Packaging Systems
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Tentative Compound Identification** & **Retention Time (min)** & **Packaging System** &
\begin{tabular}{c} **Characteristic** \\ _m/z_ \\ **(fragment) a [FOOTNOTE:a]Footnote a: Shown in the bracket is the ion \(m/z\) value used for identification if the molecular ion was not detected. \({}^{\mathrm{b}}\)\(\Delta I=\) | Experimental |—NIST Reference \(1\) |. The same stationary phase reference I value was used, but equivalent conditions cannot be guaranteed. \({}^{\mathrm{c}}\) Analyte likely to arise from packaging. \({}^{\mathrm{d}}\) Analyte identified from their fragment ions and the formula of corresponding fragment ions are given. Analyte peaks \(<\) 1\% relative response area in the respective packaging system have not been included in this table. \({}^{\mathrm{e}}\) Analyte’s have been previously reported. The fragment \(m/z\) ion, \(I\) and \(\Delta I\) values, and comparison to NIST library database are supportive of the isomers noted. & & & & \\ \hline ethyl acetate & 3.69 & CP & 77.6720 & \(-\)10.44 & N/A & [19; 20] \\ (C\({}_{4}\)H\({}_{8}\)O\({}_{2}\)) & 3.69 & CP & 100.1239 & 7.51 & 799 & [23] \\ herplane & 5.23 & CP & 100.1239 & 7.51 & (2) & [23] \\ (C\({}_{7}\)H\({}_{16}\)) & & & & & N/A & [6; 17; 18] \\ acetic acid & 3.36 & VP & 66.3920 & 6.34 & (N/A) & [6; 17; 18] \\ (C\({}_{2}\)H\({}_{4}\)O\({}_{2}\)) & & & & & 771 & [38] \\ 3-methylene-heptane \({}^{\mathrm{d}}\) & & & & & (11) & [38] \\ (C\({}_{8}\)H\({}_{16}\)) & & & & & & 789 & \\ (C\({}_{8}\)H\({}_{16}\)) & 7.19 & VP & 112.1251 & \(-\)4 & 789 & [39] \\ 3.4-dimethyl-1-octene \({}^{\mathrm{d,\,e}}\) & & & & 85.1009 & & 897 & \\ (C\({}_{10}\)H\({}_{20}\)) & & & & (C\({}_{6}\)H\({}_{13}\)) & 7.43 & (20) & Present work \\ 2-heptanal & & & & & & 917 & [40] \\ (C\({}_{7}\)H\({}_{12}\)O) & & & & & & (4) & [40] \\ 3-methylInonane \({}^{\mathrm{d,\,e}}\) & & & & 127.1487 & & 980 & \\ (C\({}_{10}\)H\({}_{22}\)) & & & & (C\({}_{9}\)H\({}_{19}\)) & 4.51 & (9) & [41] \\ hydrocarbons & & & & & N/A & \\ (CH\({}_{4}\)N\({}_{2}\)O\({}_{2}\)) & 2.71 & VP & 77.2447 & 1.19 & & (N/A) & [42] \\ 3,7-dimethylInonane \({}^{\mathrm{d,\,e}}\) & & & & & 127.1458 & & 983 & \\ (C\({}_{11}\)H\({}_{24}\)) & & & & (C\({}_{9}\)H\({}_{19}\)) & 10.44 & (3) & [43; 44; 45] \\ acetaldehyde & & & & & N/A & \\ (C\({}_{2}\)H\({}_{4}\)O) & & & & & & N/A & \\ dimethyl disulphide & & & & & & 785 & \\ (C\({}_{2}\)H\({}_{6}\)S\({}_{2}\)) & 7.09 & VP & 93.992 & 5.82 & & (3) & [6; 7; 46] \\ \hline \hline \end{tabular} \({}^{\mathrm{a}}\) Shown in the bracket is the ion \(m/z\) value used for identification if the molecular ion was not detected. \({}^{\mathrm{b}}\)\(\Delta I=\) | Experimental |—NIST Reference \(1\) |. The same stationary phase reference I value was used, but equivalent conditions cannot be guaranteed. \({}^{\mathrm{c}}\) Analyte likely to arise from packaging. \({}^{\mathrm{d}}\) Analyte identified from their fragment ions and the formula of corresponding fragment ions are given. Analyte peaks \(<\) 1\% relative response area in the respective packaging system have not been included in this table. \({}^{\mathrm{e}}\) Analyte’s have been previously reported. The fragment \(m/z\) ion, \(I\) and \(\Delta I\) values, and comparison to NIST library database are supportive of the isomers noted. & & & \\ \end{tabular}
\end{table} 
Table 1: \(Cont.\)could be due to that fact that there are few reports that investigate the volatiles from raw beef. Sulphurous compounds are formed due to the breakdown of the amino acids cysteine and methionine, which in turn are produced from proteins present in meat by microbes that are likely introduced at the slaughterhouse [48]. The detection of acetoin in all three packaging formats was also expected.