Table 4.
Volatile compound content (*) detected for rapeseed oil: unheated (T0), after 10 and 20 days of treatment at 65 °C (T1 and T2, respectively) and after 90 min at 180 °C (T3).
| Volatile | KI | T0 | T1 | T2 | T3 |
|---|---|---|---|---|---|
| Hydrocarbons | |||||
| 2-E-octene | 809 | ND | ND | 1545 ± 145 | 1888 ± 536 |
| 2-Z-octene | 816 | ND | ND | 1228 ± 147 | ND |
| Total hydrocarbons (Σ) | ND | ND | 2773 ± 292 | 1888 ± 536 | |
| Aldehydes | |||||
| (E)-2-Pentenal | 748 | 3975 ± 250 d | 34,862 ± 1209 c | 33,744 ± 799 b | 22,541 ± 723 a |
| Hexanal | 803 | 32,637 ± 2008 a | 46,946 ± 868 b | 54,638 ± 2225 c | 90,102 ± 3954 d |
| (E)-2-Hexenal | 851 | ND | 4812 ± 161 a | 7289 ± 406 b | 11,901 ± 409 c |
| Heptanal | 901 | 1328 ± 123 a | 4654 ± 403 b | 5570 ± 469 c | 16,596 ± 677 d |
| (E,E)-2,4-Hexadienal | 908 | ND | 17,550 ± 4010 a | 25,314 ± 1190 b | 14,631 ± 1445 a |
| (E)-2-Heptenal | 954 | 2166 ± 318 a | 59,008 ± 738 b | 56,474 ± 2760 b | 109,829 ± 6641 c |
| (E,E)-2,4-Heptadienal | 995 | 28,023 ± 1536 a | 281,746 ± 9605 c | 253,474 ± 4111 b | 338,112 ± 13,035 d |
| Octanal | 1002 | 7425 ± 965 a | 38,155 ± 3868 b | 48,629 ± 4496 c | 108,931 ± 8382 d |
| 2,4-Heptadienal | 1009 | 2024 ± 208 a | 123,654 ± 4945 b | 142,568 ± 4930 c | 406,889 ± 12,144 d |
| (E)-2-Octenal | 1056 | ND | 20,883 ± 713 a | 24,107 ± 1092 b | 42,758 ± 1391 c |
| Nonanal | 1103 | 1783 ± 198 a | 25,040 ± 905 b | 29,285 ± 1501 b | 203,362 ± 9729 c |
| Nonenal | 1158 | ND | ND | 11,815 ± 1128 a | 25,786 ± 988 b |
| (E,E)-2,4-Decadienal | 1291 | ND | 8795 ± 900 a | 15,114 ± 1670 a | 199,682 ± 39,899 b |
| Total aldehydes (Σ) | 79,361 ± 5606 a | 666,105 ± 28,325 b | 708,021 ± 26,777 c | 1,591,120 ± 98,967 d | |
| Ketones | |||||
| 3-Hexen-2-one | 840 | ND | 808 ± 108 a | ND | 5386 ± 229 b |
| 2-Heptanone | 890 | ND | 3011 ± 326 a | 3759 ± 406 b | 4362 ± 423 c |
| Ethanone,1-(1-cyclohexen-1-l) | 935 | ND | 148,467 ± 38,941 | 155,965 ± 2756 | 170,795 ± 9153 |
| 1-Octen-3-one | 977 | ND | 1015 ± 103 a | 890 ± 122 a | 1513 ± 220 b |
| 3-Octanone | 986 | ND | ND | ND | 5658 ± 705 |
| 6-Methyl-5-hepten-2-one | 988 | ND | 10,466 ± 357 a | 12,181 ± 198 b | ND |
| 3-Octen-2-one | 1038 | 1845 ± 72 a | 9629 ± 353 c | 12,298 ± 426 b | 3318 ± 230 d |
| (E,E)-3,5-Octadien-2-one | 1070 | ND | 54,005 ± 968 c | 49,940 ± 1116 b | 5106 ± 644 a |
| 3,5-Octadien-2-one | 1092 | ND | 45,824 ± 1023 a | 51,604 ± 1782 b | ND |
| Total ketones (Σ) | 1845 ± 72 a | 273,225 ± 42,179 c | 286,637 ± 6806 b | 196,138 ± 7310 d | |
| Acids | |||||
| Hexanoic | 992 | 2977 ± 149 a | 20,149 ± 971 c | 27,373 ± 1747 d | 5657 ± 421 b |
| Octanoic | 1176 | ND | ND | ND | 4000 ± 1309 |
| Nonanoic | 1276 | ND | ND | ND | 8768 ± 2728 |
| Total acids (Σ) | 2977 ± 149 a | 20,149 ± 971 b | 27,373 ± 1747 b | 18,425 ± 4458 b | |
| Alcohols | |||||
| 1-Pentanol | 762 | 2554 ± 123 a | ND | ND | 26,434 ± 703 b |
| 1-Hexanol | 870 | 6599 ± 255 d | 1628 ± 77 b | 1239 ± 111 a | 2223 ± 295 c |
| 1-Heptanol | 970 | ND | ND | ND | 11,367 ± 923 |
| 1-Octen-3-ol | 979 | 638 ± 78 a | 14,992 ± 436 c | 13,249 ± 622 b | 18,115 ± 1042 d |
| 1-Octanol | 1072 | ND | ND | ND | 17,633 ± 631 |
| Total alcohols (Σ) | 9791 ± 456 a | 16,620 ± 513 b | 14,488 ± 733 b | 75,772 ± 3594 c | |
| Furans | |||||
| Furan, 2-Pentyl | 991 | 7891 ± 1559 a | 58,918 ± 2481 c | 82,661 ± 4614 d | 50,624 ± 2529 b |
| Total furans (Σ) | 7891 ± 1559 a | 58,918 ± 2481 c | 82,661 ± 4614 d | 50,624 ± 2529 b | |
| Terpenes | |||||
| Alpha-pinene | 929 | 368 ± 25 | ND | ND | ND |
| Limonene | 1025 | 1897 ± 207 | 1871 ± 147 | 1835 ± 572 | ND |
| Total terpenes (Σ) | 2265 ± 232 | 1871 ± 147 | 1835 ± 572 | ND | |
| Total Σ | 104,130 ± 8074 a | 1,036,888 ± 74,616 b | 1,123,788 ± 41,541 b | 1,933,967 ± 22,096 c |
(*) Volatile compounds are expressed per area/sample weight (g) × 103. Values of means ± standard deviations. Values with different letters within rows are statistically different p < 0.05 according to the Bonferroni post hoc test. KI: Kovats index. ND:not detected.