Table 5.
Volatile compound content (*) detected for grape seed 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 | |||||
| 1-Octene | 793 | 1328 ± 133 a | ND | ND | 2043 ± 346 b |
| 2-E-octene | 809 | 5904 ± 500 bc | 4222 ± 432 a | 6663 ± 531 c | 5456 ± 1070 b |
| 2-Z-octene | 816 | 2495 ± 264 bc | 1701 ± 129 a | 2827 ± 338 c | 2178 ± 514 b |
| Total hydrocarbons (Σ) | 9727 ± 897 | 5923 ± 561 | 9490 ± 869 | 9677 ± 1930 | |
| Aldehydes | |||||
| (E)-2-Pentenal | 748 | ND | 2579 ± 153 | 3011 ± 622 | ND |
| Hexanal | 803 | 35,088 ± 5643 a | 66,528 ± 4110 b | 66,147 ± 3541 b | 137,213 ± 12,039 c |
| (E)-2-Hexenal | 851 | 747 ± 103 a | 23,070 ± 1323 b | 21,868 ± 1717 b | 30,594 ± 3326 c |
| Heptanal | 901 | 1432 ± 176 a | 5832 ± 1322 b | 5033 ± 504 b | 11,212 ± 1614 c |
| (E)-2-Heptenal | 954 | 8510 ± 596 a | 208,336 ± 8588 b | 199,345 ± 11,880 b | 270,474 ± 35,611 c |
| (E,E)-2,4-Heptadienal | 995 | 1644 ± 193 a | 24,758 ± 1671 b | 28,718 ± 3293 b | 46,073 ± 5513 c |
| Octanal | 1002 | 2698 ± 321 a | 31,674 ± 2623 b | 38,800 ± 3559 b | 79,232 ± 12,472 c |
| 2,4-Heptadienal | 1009 | ND | 6097 ± 487 a | 7755 ± 524 b | 17,729 ± 1459 c |
| (E)-2-Octenal | 1056 | 1484 ± 142 a | 57,966 ± 9692 b | 79,807 ± 8360 c | 86,214 ± 12,884 c |
| Nonanal | 1103 | 693 ± 65 a | 3789 ± 553 a | 2914 ± 229 a | 56,156 ± 6510 b |
| (E,E)-2,4-Octadienal | 1107 | ND | 860 ± 68 a | ND | 2246 ± 300 b |
| Nonenal | 1158 | ND | 7134 ± 365 a | 13,697 ± 691 b | 16,610 ± 1021 c |
| 2,4-Nonadienal | 1212 | ND | 4120 ± 244 a | 4784 ± 367 a | 13,199 ± 2519 b |
| (E,E)-2,4-Decadienal | 1291 | ND | 13,561 ± 964 a | 20,207 ± 1463 a | 672,012 ± 168,979 b |
| 2,4-Decadienal | 1317 | ND | 33,428 ± 2592 a | 56,523 ± 4908 a | 727,265 ± 142,179 b |
| Total aldehydes (Σ) | 52,296 ± 7239 a | 489,732 ± 34,255 b | 548,612 ± 22,893 b | 2,166,229 ± 236,907 c | |
| Ketones | |||||
| 2-Heptanone | 890 | ND | 7908 ± 804 b | 9069 ± 896 a | 5442 ± 1112 c |
| 1-Octen-3-one | 977 | ND | 2898 ± 92 a | 2337 ± 293 b | 2312 ± 566 a |
| 3-Octanone | 986 | ND | 2245 ± 123 c | 2936 ± 258 b | 1522 ± 290 a |
| 3-Octen-2-one | 1038 | ND | 26,868 ± 1438 b | 32,210 ± 6306 c | 5951 ± 951 a |
| (E,E)-3,5-Octadien-2-one | 1070 | ND | 1332 ± 137 | ND | ND |
| 3,5-Octadien-2-one | 1092 | ND | 1521 ± 243 | ND | ND |
| Total ketones (Σ) | ND | 42,772 ± 2837 b | 46,552 ± 2077 b | 15,227 ± 2919 a | |
| Acids | |||||
| Hexanoic | 992 | 3202 ± 589 a | 72,354 ± 10,221 b | 89,608 ± 8801 c | 8441 ± 2634 a |
| Total acids (Σ) | 3202 ± 589 a | 72,354 ± 10,221 b | 89,608 ± 8801 c | 8441 ± 2634 a | |
| Alcohols | |||||
| 1-Pentanol | 762 | 1243 ± 194 a | 3902 ± 541 a | 3868 ± 405 a | 61,807 ± 5740 b |
| 1-Hexanol | 870 | ND | 1796 ± 109 a | 2188 ± 239 b | 1809 ± 309 a |
| 1-Heptanol | 970 | ND | ND | ND | 5429 ± 892 |
| 1-Octen-3-ol | 979 | 997 ± 232 a | 53,096 ± 2482 b | 48,707 ± 2419 b | 51,296 ± 5752 b |
| 2-Octen-1-ol | 1068 | ND | ND | ND | 5203 ± 505 |
| 1-Octanol | 1072 | ND | ND | ND | 8359 ± 901 |
| Total alcohols (Σ) | 2240 ± 426 a | 58,794 ± 3132 b | 54,763 ± 3063 b | 133,903 ± 14,099 c | |
| Furans | |||||
| Furan, 2-Pentyl | 991 | 7101 ± 506 a | 100,415 ± 13,052 c | 163,693 ± 17,544 d | 57,458 ± 9410 b |
| Total furans (Σ) | 7101 ± 506 a | 100,415 ± 13,052 c | 163,693 ± 17,544 d | 57,458 ± 9410 b | |
| Terpenes | |||||
| Alpha-pinene | 929 | 274 ± 202 | ND | ND | ND |
| Para-cymene | 1022 | 3002 ± 251 | ND | ND | ND |
| Limonene | 1025 | 3955 ± 3676 a | 13,349 ± 166 b | ND | 907 ± 423 a |
| Total terpenes (Σ) | 7231 ± 4129 b | 13,349 ± 166 c | ND | 907 ± 423 a | |
| Total Σ | 81,797 ± 13,786 a | 783,339 ± 64,224 b | 912,722 ± 51,226 b | 2,391,856 ± 217,406 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.