TABLE 3.
Concentrations of volatile free fatty acids and volatile components identified in the four sourdoughs propagated under firm and liquid conditions for different times
| Acid or componenta | Concnb |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MAI | MAVL | MAVF | MBI | MBVL | MBVF | MCI | MCVL | MCVF | AI | AVL | AVF | |
| VFFA | ||||||||||||
| Acetic acid | 514cd | 446d | 774bc | 863b | 824b | 1040a | 459d | 643c | 1178a | 283e | 953ab | 847b |
| 2-Methyl-propionic acid | 0.27bc | 0.40b | 0.33b | 0.20c | 0.40b | 0.38b | 0.20c | 0.36b | 0.52a | 0.08d | 0.51a | 0.31b |
| Caproic acid | 2.37a | 0.96c | 2.82a | 2.56a | 1.38b | 2.69a | 2.03a | 1.86ab | 3.13a | 0.71c | 0.98c | 0.90c |
| VOC | ||||||||||||
| Acetaldehyde | 1.6E6c | 3.5E6b | 2.4E6bc | 1.8E6c | 4.7E6a | 4.8E6a | 3.5E6b | 6.1E6a | 4.7E6a | 1.7E6c | 3.0Eb | 5.7E6a |
| Octanal | 3.7E5bc | 5.9E5b | 3.6E5bc | 5.6E5b | 6.9E5b | 4.0E5b | 2.9E5c | 7.1E5b | 5.4E5b | 5.0E5b | 1.2E6a | 4.1E5b |
| Nonanal | 1.4E6c | 2.0E5b | 2.1E6b | 2.0E5b | 2.7E5b | 2.0E5b | 1.2E5c | 3.4E6ab | 2.2E5b | 2.5E5b | 4.0E5a | 2.3E5b |
| Decanal | 1.2E5c | 4.3E5ab | 3.5E5b | 4.2E5ab | 5.0E5a | 5.1E5a | 2.1E5c | 4.9E5a | 5.1E5a | 3.8E5b | 4.9E5a | 3.7E5b |
| 2-Butenal (Z) | 3.6E4c | 5.0E4b | 3.6E4c | 4.3E4b | 5.2Ea | 4.5E4b | 4.5E4b | 4.6E4b | 3.8E4b | 3.1E4bc | 4.2E4b | 2.5E4c |
| 2-Pentenal | 4.4E5ab | 2.4E5bc | 3.7E5b | 3.0E5b | 2.6E5bc | 2.8E5b | 5.0E5a | 3.2E5b | 4.3E5ab | 4.1E5ab | 2.4E5bc | 2.0E5c |
| 3-Methyl-butanal | 1.7E5c | 6.0E5b | 1.4E5c | 1.5E5c | 2.1E6a | 1.0E6ab | 4.9E5bc | 2.0E6a | 1.3E6ab | 1.5E5c | 7.0E5b | 3.2E5bc |
| Benzeneacetaldehyde | 2.9E5c | 1.5E6b | 1.0E5c | 2.6E5c | 4.1E6a | 7.7E5bc | 1.9E5c | 2.9E6ab | 9.3E5bc | 2.0E5c | 6.5E5bc | 1.9E5c |
| Ethanol | 9.7E7b | 2.1E8a | 3.5E7c | 2.2E8a | 3.7E8a | 3.3E8a | 2.7E8a | 3.8E8a | 3.8E8a | 1.6E8a | 1.8E8a | 3.3E8a |
| 1-Butanol | 7.8E5b | 1.2E6ab | 9.3E5b | 9.6E5b | 1.7E6a | 1.7E6a | 8.3E5bc | 1.7E6a | 1.6E6a | 6.8E5c | 7.9E5b | 6.8E5c |
| 2-Butanol | 5.1E5a | 1.4E5a | 8.6E4b | 8.4E5a | 0.0E0c | 0.0E0c | 7.9E5a | 8.8E3bc | 2.6E4bc | 1.5E5a | 2.0E2c | 2.0E2c |
| 2-Methyl-1-propanol | 4.9E5c | 4.5E6b | 2.4E5c | 2.8E5c | 1.3E7a | 6.0E6b | 1.4E6bc | 9.8E6ab | 4.9E6b | 6.1E5bc | 3.6E6b | 4.5E6b |
| 3-Methyl-1-butanol | 7.1E6c | 8.3E7b | 3.2E6c | 2.3E6c | 2.1E8a | 1.1E8a | 1.8E7ab | 1.6E8a | 8.7E7b | 4.2E6c | 8.5E7b | 4.4E7ab |
| 2-Methyl-1-butanol | 1.4E6bc | 1.7E7ab | 7.7E5c | 6.6E5c | 4.0E7a | 2.3E7ab | 4.6E6b | 3.6E7a | 1.9E7ab | 4.5E5c | 9.8E6b | 4.1E6b |
| 3-Octanone | 1.1E5b | 1.3E5ab | 8.7E4bc | 1.0E5b | 1.1E5b | 8.1E4bc | 6.5E4c | 1.3E5ab | 9.7E4b | 1.0E5b | 1.8E5a | 7.5E4bc |
| 3-Methyl-2-butanone | 1.3E5b | 1.3E5b | 7.4E4bc | 1.5E5ab | 1.8E5a | 1.1E5b | 1.1E5b | 1.4E5b | 9.9E4bc | 1.2E5b | 1.3E5b | 5.6E4c |
| Methyl acetate | 3.1E5bc | 7.0E5b | 6.3E5b | 3.7E5bc | 4.3E5b | 1.5E6a | 5.7E5b | 5.2E5b | 1.4E6a | 2.8E5c | 7.3E5b | 1.4E6a |
| Methyl benzoate | 3.9E4b | 6.6E3c | 1.0E4bc | 8.8E4a | 1.5E4bc | 1.7E4bc | 3.1E4b | 1.6E4bc | 2.1E4bc | 4.2E4b | 5.5E3c | 9.1E3c |
| Ethyl acetate | 9.6E7d | 1.8E8c | 1.1E8b | 1.6E8c | 2.9E8a | 3.1E8a | 1.1E8d | 2.8E8b | 2.3E8ab | 1.2E8d | 1.7E8c | 2.1E8b |
| Propyl acetate | 1.2E5c | 9.0E5b | 1.4E5c | 3.8E5bc | 3.6E6a | 2.6E6a | 2.9E5bc | 3.0E6a | 1.2E6a | 1.4E5c | 8.8E5b | 1.4E6a |
| 2-Methyl-propyl acetate | 4.5E4c | 1.8E6a | 3.3E4c | 6.3E4c | 5.8E6a | 3.8E6a | 1.8E5b | 4.3E6a | 1.6E6a | 5.3E4c | 1.4E6a | 2.0E6a |
| 3-Methyl-butyl acetate | 4.5E5c | 2.5E7a | 2.9E5c | 3.1E5c | 5.3E7a | 4.0E7a | 1.9E6b | 4.2E7a | 2.0E7a | 2.5E5c | 3.0E7a | 1.3E7a |
| 2-Methyl-butyl acetate | 1.1E5bc | 4.3E6b | 8.6E4c | 9.7E4c | 1.3E7a | 9.2E6ab | 4.6E5bc | 9.7E6ab | 4.3E6b | 3.9E4c | 2.6E6b | 1.1E6b |
| 3-Methyl-butyl hexanoate | 3.1E3bc | 2.2E4b | 2.0E2c | 3.5E3bc | 7.9E4a | 3.4E4b | 0.0E0c | 7.6E4a | 2.6E4b | 9.4E2c | 6.5E3bc | 2.9E3bc |
| 2-Phenyl-ethyl acetate | 1.3E5d | 5.4E5bc | 3.9E3g | 9.4E4e | 1.3E6a | 2.0E5c | 3.7E4f | 7.3E5b | 3.7E5c | 7.5E4ef | 1.6E5d | 9.0E4e |
| Carbon disulfide | 1.0E4cd | 1.6E4c | 2.8E4b | 3.0E4b | 1.1E4cd | 2.7E4b | 2.9E4b | 8.7E3d | 2.8E4b | 3.4E4b | 1.9E4c | 6.5E4a |
| Dimethyl-trisulfide | 4.4E3c | 3.2E3cd | 4.8E3c | 7.6E3b | 4.8E3c | 9.1E3a | 7.6E3b | 4.8E3c | 8.1E3ab | 4.7E3c | 2.1E3d | 9.9E3a |
| 3-Methyl-furan | 2.0E5ab | 3.0E4d | 1.8E5b | 2.1E5ab | 5.3E3e | 2.6E4d | 1.6E5b | 5.1E3e | 8.8E4c | 2.4E5a | 1.9E4d | 4.9E4cd |
| 2-Hexyl-furan | 2.1E5b | 4.3E5a | 2.5E5b | 2.6E5b | 4.5E5a | 1.9E5b | 2.0E5b | 3.0E5b | 2.1E5b | 1.9E5bc | 4.7E5a | 1.4E5c |
| Diethyl-ether | 4.8E3c | 4.5E4ab | 2.2E4b | 5.9E3c | 5.6E4a | 6.0E4a | 3.8E4ab | 6.1E4a | 6.7E4a | 1.6E4bc | 5.5E4a | 6.5E4a |
| Decane | 3.1E5cd | 9.6E5b | 2.3E5d | 4.6E5c | 8.1E5b | 3.0E5d | 2.3E5d | 4.2E5c | 3.4E5cd | 7.7E5b | 1.1E6a | 2.5E5d |
| Nonadiene1 | 1.3E5b | 6.3E4d | 1.0E5bc | 1.6E5b | 4.6E4e | 1.2E5bc | 1.3E5b | 4.6E4e | 8.2E4c | 1.8E5ab | 1.4E5b | 3.0E5a |
| Nonadiene2 | 1.5E5b | 6.5E4d | 1.2E5c | 1.7E5bc | 5.0E4d | 1.4E5b | 1.5E5b | 5.3E4d | 1.0E5c | 2.0E5ab | 1.4E5b | 3.1E5a |
| Ethyl,3-methyl-benzene | 1.5E5b | 8.3E4c | 9.5E4c | 2.2E5a | 8.7E4c | 1.6E5b | 1.4E5b | 1.1E5bc | 1.1E5bc | 1.6E5b | 8.8E4c | 1.1E5bc |
| 1-Methyl,2-ethyl-benzene | 2.1E5ab | 1.1E5b | 1.1E5b | 3.5E5a | 9.9E4c | 1.7E5b | 2.0E5ab | 1.3E5b | 1.4E5b | 2.2E5ab | 1.2E5b | 2.1E5ab |
| 1,2,3-Trimethyl-benzene | 2.1E5b | 1.3E5d | 1.4E5cd | 2.9E5a | 1.4E5cd | 2.3E5b | 2.1E5b | 1.8E5bc | 1.6E5c | 2.2E5b | 1.3E5d | 1.6E5c |
| 1,3,5-Trimethyl-benzene | 7.4E5b | 4.1E5c | 4.5E5c | 1.2E6a | 3.7E5c | 7.2E5b | 7.3E5b | 4.9E5c | 5.5E5bc | 8.1E5b | 4.6E5c | 5.8E5bc |
| 1,2,4-Trimethyl-benzene | 2.9E5b | 1.7E5bc | 1.9E5bc | 4.5E5a | 1.5E5c | 2.6E5b | 2.8E5b | 1.9E5bc | 2.3E5b | 3.0E5b | 2.0E5b | 2.2E5b |
| Naphtalene | 7.2E5c | 8.1E5bc | 9.4E5bc | 7.4E5c | 1.1E6b | 1.0E6b | 6.0E5c | 1.4E6a | 1.5E6a | 1.1E6b | 1.3E6ab | 1.5E6a |
| Alpha-pinene | 6.3E4d | 1.0E5b | 7.2E4c | 8.0E4c | 9.6E4bc | 6.6E4d | 7.1E4c | 1.5E5a | 7.6E4c | 7.5E4c | 1.6E5a | 6.6E4d |
| Camphene | 7.1E4e | 7.6E4e | 1.1E5cd | 8.0E4e | 8.7E4e | 1.3E5cd | 7.4E4e | 1.0E5d | 1.1E5d | 4.0E5a | 1.9E5c | 2.8E5b |
| Beta-pinene | 5.4E4cd | 8.0E4c | 4.7E4d | 8.6E4c | 1.2E5ab | 1.3E5a | 7.8E4c | 1.0E5b | 1.2E5ab | 5.7E4cd | 8.3E4c | 4.1E4d |
| Beta-myrcene | 3.2E5a | 1.9E5c | 2.5E5b | 3.3E5a | 2.4E5b | 3.2E5a | 3.2E5a | 2.4E5b | 3.0E5a | 2.2E5b | 1.7E5c | 2.4E5b |
| Delta-carene | 2.8E4c | 4.4E4b | 6.3E4ab | 3.1E4bc | 4.8E4b | 7.1E4a | 2.6E4c | 7.5E4a | 5.6E4ab | 2.9E4c | 3.4E4bc | 4.2E4b |
| p-Cymene | 3.1E5c | 2.9E5d | 5.1E5a | 3.1E5c | 3.0E5d | 4.4E5b | 2.6E5d | 3.6E5c | 4.9E5b | 2.9E5d | 4.6E5b | 5.3E5a |
| 1(1-methyl-1-ethenyl)-4-methyl-benzene | 6.1E4c | 5.5E4cd | 8.8E4a | 5.8E4cd | 6.5E4c | 7.6E4b | 5.0E4d | 8.5E4ab | 7.9E4b | 4.9E4d | 9.0E4a | 9.3E4a |
a
Compounds that, based on the literature (44–47), may have an impact on the aroma of sourdough baked goods are in boldface.
b
VFFA are reported in ppm and VOC in arbitrary units of area. Only VOC that showed variation (P ≤ 0.05) between samples are reported. The ingredients and technological parameters used for daily sourdough backslopping are reported in Table 1. Times were as follows: 1 (I) and 28 (V) days. The data are the means of three independent experiments, and values in the same row followed by different lowercase letters (a to g) differ significantly (P ≤ 0.05).