Table 3.
Evolution of volatile compounds (µg/kg expressed as 4-methyl-2-pentanol) of the soup *.
| Fresh | Frozen | |||
|---|---|---|---|---|
| T0 | T1 | T2 | ||
| Aldehydes | ||||
| Acetaldehyde | 40.4 ± 0.6 a | 44.4 ± 3.4 a | 42.9 ± 2.2 a | 44.1 ± 2.2 a |
| Pentanal | 229.0 ± 3.7 a | 235.6 ± 6.6 a | 230.7 ± 9.1 a | 230.0 ± 12.7 a |
| Hexanal | 200.0 ± 18.0 a | 192.0 ± 6.5 a | 206.2 ± 11.0 a | 222.0 ± 12.7 a |
| (E)-2-Heptenal | 36.7 ± 3.2 a | 32.9 ± 2.4 a | 33.4 ± 1.8 a | 36.3 ± 2.9 a |
| Nonanal | 87.2 ± 6.3 a | 87.6 ± 4.0 a | 90.3 ± 6.8 a | 89.5 ± 1.4 a |
| 2,4-Decadienal | 56.2 ± 3.4 a | 61.1 ± 2.1 a | 64.6 ± 1.0 a | 68.4 ± 5.1 a |
| Sum of aldehydes | 649.5 ± 19.9 a | 653.6 ± 11.1 a | 668.1 ± 16.1 a | 690.2 ± 19.1 a |
| Alcohols | ||||
| 2-Methyl-1-butanol | 8.0 ± 0.8 a | 8.0 ± 0.3 a | 8.2 ± 0.5 a | 7.0 ± 0.7 a |
| 1-Pentanol | 116.0 ± 5.2 a | 108.3 ± 4.3 a | 117.1 ± 15.5 a | 126.9 ± 2.1 a |
| 1-Hexanol | 142.6 ± 3.0 ab | 159.5 ± 13.1 a | 138.2 ± 3.6 ab | 119.9 ± 1.2 b |
| Sum of alcohols | 266.5 ± 6.1 a | 275.8 ± 13.8 a | 263.5 ± 16.0 a | 253.8 ± 2.5 a |
| Ketones | ||||
| Acetoin | 106.6 ± 4.4 a | 111.8 ± 6.4 a | 123.5 ± 18.6 a | 101.6 ± 9.0 a |
| Terpenes | ||||
| Limonene | 258.5 ± 3.3 a | 254.2 ± 9.4 a | 310.7 ± 15.9 b | 257.8 ± 17.5 a |
| α-Pinene | 6424.7 ± 157.7 a | 6413.0 ± 128.5 a | 6439.0 ± 106.9 a | 6449.5 ± 117.6 a |
| β-Pinene | 1436.1 ± 50.2 a | 1454.5 ± 46.5 a | 1396.4 ± 121.3 a | 1408.9 ± 237.9 a |
| β-Myrcene | 3302.7 ± 33.3 a | 3326.1 ± 54.4 a | 3429.1 ± 8.7 a | 3300.5 ± 46.2 a |
| γ-Terpinene | 1243.7 ± 14.2 a | 1228.3 ± 96.6 a | 1227.3 ± 46.9 a | 1205.0 ± 77.8 a |
| Caryophyllene | 652.0 ± 11.4 a | 667.1 ± 2.5 a | 646.5 ± 43.7 a | 674.1 ± 23.0 a |
| Sum of terpenes | 13,317.7 ± 169.8 a | 13,343.2 ± 176.3 a | 13,449.1 ± 174.9 a | 13,295.9 ± 281.9 a |
| Sulphur compounds | ||||
| Dimethyl sulfide | 97.4 ± 3.4 a | 102.9 ± 6.7 a | 99.9 ± 2.5 a | 110.1 ± 7.4 a |
| Dipropyl disulfide | 40.9 ± 2.5 a | 43.1 ± 3.0 a | 41.2 ± 2.2 a | 50.7 ± 3.9 a |
| Sum of sulphur compounds | 138.3 ± 4.2 a | 146.0 ± 7.4 a | 141.0 ± 3.3 a | 160.8 ± 8.3 a |
| Furans | ||||
| Furfural | 69.5 ± 4.5 a | 70.6 ± 4.0 a | 66.9 ± 0.0 a | 75.8 ± 7.6 a |
| 2-Pentyl-furan | 304.4 ± 18.8 a | 299.0 ± 12.8 a | 399.3 ± 24.4 b | 360.5 ± 28.6 ab |
| Sum of the furans | 373.9 ± 20.3 a | 369.6 ± 17.0 a | 466.1 ± 24.8 a | 436.3 ± 31.9 a |
* The results are the mean of two determinations ± the standard deviation. The comparison between the different storage times was carried out by one-way ANOVA. Different lowercase letters indicate a statistically significant difference (p < 0.05). Fresh = fresh soup (not frozen); Frozen T0 = frozen soup at the time of freezing treatment; Frozen T1 = frozen soup after 35 days of storage; Frozen T2 = frozen soup after 70 days of storage.