# Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk
## 3 Results and Discussion
### SPME GC/MS Analysis
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Volatile Compound**} & \multirow{2}{*}{**RI\({}^{\prime\prime}\)**} & \multirow{2}{*}{**RI**} & \multirow{2}{*}{**Initial**} & \multicolumn{2}{c}{**RF**} & \multicolumn{2}{c}{**HTST**} & \multicolumn{2}{c}{**IF (\(-\)5 \({}^{\circ}\)C**} & \multicolumn{2}{c}{**IF (\(-\)10 \({}^{\circ}\)C)**} \\ \cline{3-11}  & & & **0 Weeks** & **2 Weeks** & **0 Weeks** & **2 Weeks** & **5 Weeks** & **2 Weeks** & **5 Weeks** & **2 Weeks** & **5 Weeks** \\ \hline Aldehydes & & & ND & ND & \(1.51\) & ND & ND & \(0.65\) & \(0.81\) & ND & \(0.54\) \\  & & & ND & ND & \((2.23)\) a & ND & ND & \((0.77)\) a & \((0.12)\) a & ND & \((0.62)\) a \\ \hline Hexanal & 783 & 775 & ND & ND & ND & ND & ND & \(0.65\) & \(0.81\) & ND & \(0.54\) \\  & & ND & ND & ND & ND & \((0.77)\) a & \((0.12)\) a & ND & \((0.62)\) a \\ \hline Nonanal & 1082 & 1084 & ND & ND & \((2.23)\) & ND & ND & ND & ND & ND \\ \hline Aliphatic & & & & & & & & & & \\ Hydrocarbons & & & & & & & & & & \\ \hline Pentane & 500 & 500 & ND & \((0.11)\) & ND & ND & ND & ND & ND & ND & ND \\ \hline Heptane & 700 & 700 & ND & ND & ND & ND & ND & ND & ND & ND & ND \\ \hline
4-methyl-heptane & 768 & 768 & \((0.60)\) a & \((0.88)\) ab & ND & \((1.06)\) b & \((0.56)\) a & \((1.39)\) ab & \((1.58)\) ab & \((0.32)\) ab & \((1.05)\) ab \\ \hline Octane & 800 & 800 & ND & \((0.22)\) a & \((0.26)\) a & ND & \((0.05)\) a & ND & \((0.40)\) a & \((0.41)\) a & ND & ND & ND \\ \hline
2,4-dimethyl-heptane & 824 & 824 & ND & \((0.17)\) & ND & \((0.38)\) a & \((0.19)\) a & \((0.08)\) a & \((0.21)\) a & ND & ND & ND \\ \hline
2,4-dimethyl-heptane & — & 840 & \((0.92)\) a & \((1.52)\) b & ND & \((2.58)\) b & \((1.08)\) b & \((2.91)\) b & \((1.70)\) ab & \((0.79)\) ab & \((2.16)\) ab \\ \hline Decane & 1000 & 1000 & ND & \((0.28)\) b & ND & ND & \((0.07)\) b & ND & ND & \(0.11\) & ND \\ \hline Aromatics & & & & \((0.44)\) ab & \((0.17)\) b & \((0.05)\) a & \((0.36)\) c & \((0.19)\) a & \((0.48)\) b & \((0.08)\) b & \((0.19)\) b & \((0.27)\) b \\ \hline Toluene & 753 & 751 & \((0.29)\) a & \((0.06)\) b & \((0.05)\) b & \((0.05)\) a & \((0.09)\) b & \((0.07)\) b & \((0.23)\) b & \((0.04)\) ab & \((0.06)\) ab & \((0.08)\) ab \\ \hline Benzene, & & & & \((0.16)\) a & \((0.19)\) a & \((0.50)\) b & ND & \((0.66)\) b & \((1.96)\) b & \((0.41)\) b & \((0.30)\) a & \((0.31)\) a & \((0.38)\) ab \\ \hline Esters & & & ND & \((0.35)\) & ND & ND & ND & ND & ND & ND & ND \\ \hline Ethyl acetate & 601 & 601 & ND & \((0.07)\) & ND & ND & ND & ND & ND & ND & ND \\ \hline Hexanoic acid, ethyl ester & 986 & 983 & ND & \((0.30)\) & ND & ND & ND & ND & ND & ND & ND \\ \hline Ketones & & & \(12.37\) & \((1.21)\) c & \((1.16)\) ab & \((1.01)\) b & \((2.88)\) a & \((1.44)\) c & \((1.10)\) b & \((0.23)\) a & \((0.70)\) b & \((2.05)\) a \\ \hline Acetone & 468 & 486 & \((0.98)\) d & \((0.75)\) ab & \((1.11)\) cd & \((2.00)\) a & \((0.41)\) a & \((0.58)\) cd & \((0.19)\) cd & \((0.73)\) d & \((1.75)\) b \\ \hline
2-butanone & 575 & 570 & \((0.50)\) c & \((0.17)\) a & \((0.17)\) c & \((0.94)\) ab & \((0.09)\) a & \((0.63)\) c & \((0.12)\) c & \((0.58)\) c & \((0.36)\) b \\ \hline
2-pentanone & 667 & 661 & ND & \((0.59)\) & ND & ND & \((1.12)\) & ND & ND & ND & ND \\ \hline
3-methyl-2-butanone & 659 & 662 & \((0.06)\) a & \((0.60)\) a & ND & ND & ND & ND & ND & \(0.54\) \\ \hline
2,4-dimethyl-3-heptanone & — & 701 & ND & \((0.06)\) & ND & ND & ND & ND & ND & ND \\ \hline
2-Heptanone & 847 & 868 & ND & \((1.10)\) & \((0.17)\) & \((0.29)\) & \((3.18)\) & ND & ND & ND & ND \\ \hline
2-Heptanone & 847 & 868 & ND & \((0.16)\) b & \((0.03)\) a & \((0.03)\) a & \((0.64)\) c & ND & ND & ND & ND & ND \\ \hline
4-methyl-2-heptanone & — & 920 & ND & \((0.17)\) & ND & \((0.40)\) a & ND & ND & ND & ND & ND \\ \hline \hline \end{tabular}
\end{table} 
Table 4: _Cont._Although the milk's profile is believed to be partially influenced by diet [52], the aroma composition found in the initial milk sample was consistent with findings in the literature [53; 12].