Table 2.
Volatile organic compounds (VOCs) expressed as μg/l of Nocellara Etnea brine samples at different salt concentrations (4, 5, 6, 8%) under controlled (E) and spontaneous fermentation (C) at 1, 60, and 120 days.
| E1 | E2 | E3 | E4 | C1 | C2 | C3 | C4 | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| RT | 1 | 60 | 120 | 1 | 60 | 120 | 1 | 60 | 120 | 1 | 60 | 120 | 1 | 60 | 120 | 1 | 60 | 120 | 1 | 60 | 120 | 1 | 60 | 120 | |
| Acids | 0.00 | 142.29 | 113.26 | 0.00 | 69.69 | 154.59 | 0.00 | 69.55 | 108.06 | 0.00 | 75.84 | 107.60 | 0.00 | 69.52 | 139.04 | 0.00 | 71.35 | 136.14 | 0.00 | 60.25 | 134.61 | 0.00 | 59.23 | 131.78 | |
| Acetic acid | 24.78 | 0.00 | 66.75bc | 63.24b | 0.00 | 45.06a | 81.84d | 0.00 | 42.76a | 58.34b | 0.00 | 48.01a | 60.21b | 0.00 | 69.52c | 108.83e | 0.00 | 70.23c | 105.24e | 0.00 | 60.25b | 103.91e | 0.00 | 59.23b | 102.85e |
| Propionic acid | 29.74 | 0.00 | 4.02c | 9.08 | 0.00 | 5.38d | 31.23e | 0.00 | 1.03b | 0.00 | 0.00 | 1.02b | 0.09a | 0.00 | 0.00 | 3.00c | 0.00 | 0.00 | 2.85c | 0.00 | 0.00 | 3.15c | 0.00 | 0.00 | 3.13c |
| Isobutyric acid | 31.43 | 0.00 | 8.96f | 7.01e | 0.00 | 1.26a | 3.04c | 0.00 | 5.39d | 1.67a | 0.00 | 5.65d | 1.88ab | 0.00 | 0.00 | 2.12ab | 0.00 | 1.12a | 2.64c | 0.00 | 0.00 | 2.36c | 0.00 | 0.00 | 2.29b |
| Butanoic acid | 35.01 | 0.00 | 2.31e | 1.78d | 0.00 | 0.94c | 4.51f | 0.00 | 0.59b | 1.52d | 0.00 | 0.89c | 1.01c | 0.00 | 0.00 | 0.25a | 0.00 | 0.00 | 0.23a | 0.00 | 0.00 | 0.95c | 0.00 | 0.00 | 0.86c |
| Hexanoic acid | 36.19 | 0.00 | 0.00 | 30.12e | 0.00 | 7.93a | 32.98e | 0.00 | 16.54cd | 45.34f | 0.00 | 17.23d | 43.21f | 0.00 | 0.00 | 15.21c | 0.00 | 0.00 | 14.21c | 0.00 | 0.00 | 12.56b | 0.00 | 0.00 | 11.99b |
| 2-Ethylheptanoic acid | 57.20 | 0.00 | 60.25d | 2.03a | 0.00 | 9.12c | 0.99a | 0.00 | 3.24a | 1.19a | 0.00 | 3.04a | 1.20a | 0.00 | 0.00 | 9.63b | 0.00 | 0.00 | 10.97b | 0.00 | 0.00 | 11.68b | 0.00 | 0.00 | 10.66b |
| Alcohol | 19.20 | 632.36 | 434.45 | 48.32 | 548.94 | 449.10 | 29.40 | 1041.55 | 1082.59 | 30.01 | 1047.93 | 1084.68 | 67.71 | 1056.92 | 2165.14 | 61.46 | 1048.11 | 2019.43 | 69.49 | 1028.98 | 1966.09 | 64.05 | 937.38 | 1961.51 | |
| Ethanol | 3.33 | 0.00 | 250.14ab | 236.95ab | 0.00 | 350.21b | 165.24a | 0.00 | 736.45c | 768.00c | 0.00 | 735.84c | 769.12c | 0.00 | 705.91c | 1754.23d | 0.00 | 694.81c | 1613.28d | 0.00 | 681.21c | 1570.21d | 0.00 | 601.25c | 1568.91d |
| Isoamylalcohol | 11.58 | 5.95a | 81.25c | 60.01b | 0.00 | 59.11b | 71.98c | 2.81a | 65.34b | 88.28c | 2.89a | 65.21b | 87.56c | 0.00 | 84.87c | 172.13d | 0.00 | 83.14c | 169.87d | 0.00 | 79.56c | 160.85d | 0.00 | 79.11c | 159.27d |
| 1-Hexanol | 19.23 | 1.03a | 9.08b | 11.56c | 0.00 | 13.03cd | 14.74d | 0.00 | 12.11c | 11.37c | 0.00 | 13.84d | 11.59c | 0.00 | 15.21d | 18.25e | 0.00 | 12.24c | 18.12e | 0.00 | 16.02d | 16.59d | 0.00 | 14.96d | 18.07e |
| cis Hexen 1 ol | 20.84 | 0.00 | 81.65c | 41.21a | 0.00 | 35.83a | 30.98a | 0.00 | 67.32b | 55.41b | 0.00 | 67.89b | 54.98b | 0.00 | 61.23b | 88.46c | 0.00 | 62.29b | 88.23c | 0.00 | 61.21b | 87.69c | 0.00 | 58.41b | 86.30c |
| 3-Octenol | 25.13 | 0.00 | 1.96c | 2.58de | 0.00 | 0.99a | 2.01c | 0.00 | 2.45d | 1.69b | 0.00 | 2.39cd | 1.72b | 0.00 | 1.20a | 3.02e | 0.00 | 2.03c | 2.91e | 0.00 | 1.45ab | 3.01e | 0.00 | 1.11a | 2.47d |
| 1-Heptanol | 25.79 | 2.36a | 9.02f | 3.99c | 3.01b | 4.96d | 5.12d | 2.07a | 5.34d | 2.79ab | 2.05a | 5.58d | 2.81ab | 3.45bc | 9.52f | 6.13e | 3.25b | 13.21g | 6.09e | 3.56bc | 11.23g | 5.99de | 3.23b | 9.98f | 5.59d |
| 1-Octanol | 31.12 | 0.00 | 21.96d | 2.46a | 14.89c | 2.78a | 12.56c | 13.12c | 11.03c | 8.42b | 12.97c | 12.01c | 9.01b | 20.31d | 21.23d | 4.01a | 20.28d | 21.43d | 3.95a | 21.59d | 24.47d | 3.54a | 20.85d | 22.83d | 3.48a |
| 1-Nonanol | 35.91 | 8.74a | 68.32c | 0.00 | 5.87a | 0.00 | 0.00 | 4.02a | 0.00 | 0.00 | 4.65a | 0.00 | 0.00 | 4.99a | 27.14b | 0.00 | 4.85a | 26.93b | 0.00 | 5.80a | 24.61b | 0.00 | 5.01a | 23.74b | 0.00 |
| Benzyl Alcohol | 47.77 | 0.00 | 43.21e | 0.00 | 0.00 | 9.18a | 16.35b | 0.00 | 29.06d | 0.00 | 0.00 | 30.15d | 0.00 | 0.00 | 21.93c | 0.00 | 0.00 | 18.36c | 0.00 | 0.00 | 20.25c | 0.00 | 0.00 | 19.26c | 0.00 |
| Phenylethyl alcohol | 50.96 | 0.00 | 62.35a | 75.69s | 0.00 | 72.85a | 130.12c | 0.00 | 112.45b | 146.62c | 0.00 | 115.02b | 147.89c | 0.00 | 105.47b | 118.91b | 0.00 | 110.29b | 116.98b | 0.00 | 105.26b | 118.21b | 0.00 | 103.61b | 117.42b |
| 1-Undecanol | 53.54 | 1.12a | 1.59a | 0.00 | 21.92d | 0.00 | 0.00 | 7.38c | 0.00 | 0.00 | 7.45c | 0.00 | 0.00 | 36.27e | 3.21b | 0.00 | 31.22e | 3.38b | 0.00 | 36.44e | 3.71b | 0.00 | 32.98e | 3.12b | 0.00 |
| 1-Dodecanol | 63.35 | 0.00 | 1.83a | 0.00 | 2.63b | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 2.69b | 0.00 | 0.00 | 1.86a | 0.00 | 0.00 | 2.10a | 0.00 | 0.00 | 1.98a | 0.00 | 0.00 |
| Esters | 0.00 | 392.42 | 287.06 | 0.00 | 287.25 | 434.10 | 0.00 | 346.49 | 490.94 | 0.00 | 356.58 | 480.07 | 0.00 | 379.66 | 626.99 | 0.00 | 247.02 | 458.30 | 0.00 | 375.88 | 641.68 | 0.00 | 378.62 | 640.34 | |
| Ethyl acetate | 2.75 | 0.00 | 126.38a | 127.54a | 0.00 | 127.91a | 150.52a | 0.00 | 134.65a | 197.56ab | 0.00 | 140.83a | 189.12ab | 0.00 | 201.30b | 347.21c | 0.00 | 154.28a | 256.81bc | 0.00 | 202.70b | 352.42c | 0.00 | 205.61b | 350.14c |
| Ethyl propanoate | 3.56 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 7.12 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Ethyl butanoate | 4.07 | 0.00 | 0.00 | 0.00 | 0.00 | 1.87a | 8.96c | 0.00 | 2.30a | 10.45d | 0.00 | 2.19a | 11.02d | 0.00 | 8.86c | 0.00 | 0.00 | 4.56b | 0.00 | 0.00 | 9.86cd | 0.00 | 0.00 | 8.88c | 0.00 |
| Butanoic acid 2 methylester | 5.44 | 0.00 | 6.53a | 11.04b | 0.00 | 14.76b | 93.11f | 0.00 | 5.67a | 11.98b | 0.00 | 6.01a | 12.86b | 0.00 | 24.39c | 69.23e | 0.00 | 13.32b | 62.13d | 0.00 | 23.62c | 74.37e | 0.00 | 25.84c | 72.86e |
| Butanoic acid 3 methylester | 5.85 | 0.00 | 2.86a | 5.42b | 0.00 | 12.90d | 65.01f | 0.00 | 4.34b | 17.63e | 0.00 | 4.16b | 17.84e | 0.00 | 2.51a | 9.89c | 0.00 | 1.23a | 9.61c | 0.00 | 2.84a | 9.56c | 0.00 | 2.51a | 9.99c |
| Isoamylacetate | 7.47 | 0.00 | 2.69a | 16.31b | 0.00 | 9.31b | 11.82b | 0.00 | 4.53a | 14.11b | 0.00 | 4.86a | 14.82b | 0.00 | 3.22a | 45.23c | 0.00 | 1.75a | 42.18c | 0.00 | 3.65a | 48.51c | 0.00 | 3.46a | 47.02c |
| Hexanoic acid methylester | 9.90 | 0.00 | 0.00 | 2.18 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
| Ethyl hexanoate | 12.29 | 0.00 | 16.89d | 13.02cd | 0.00 | 8.75b | 3.99a | 0.00 | 11.09c | 18.34d | 0.00 | 11.21c | 19.05d | 0.00 | 9.06b | 3.98a | 0.00 | 4.56a | 3.21a | 0.00 | 9.17b | 4.57a | 0.00 | 9.01b | 4.32a |
| Ethyl lactate | 18.49 | 0.00 | 61.53e | 56.25e | 0.00 | 34.39c | 42.98d | 0.00 | 42.34d | 80.67f | 0.00 | 42.76d | 81.12f | 0.00 | 23.95b | 51.74e | 0.00 | 11.98a | 32.12c | 0.00 | 22.86b | 45.79d | 0.00 | 23.12b | 49.56de |
| Butanoic acid 2-hydroxy-3-methylester | 23.10 | 0.00 | 4.02a | 4.41a | 0.00 | 0.00 | 4.01a | 0.00 | 0.00 | 3.40a | 0.00 | 0.00 | 3.98a | 0.00 | 0.00 | 7.98c | 0.00 | 0.00 | 6.36b | 0.00 | 0.00 | 8.82c | 0.00 | 0.00 | 8.17c |
| Ethyl octanoate | 23.44 | 0.00 | 9.63d | 1.84b | 0.00 | 1.78b | 0.34a | 0.00 | 2.66bc | 0.32a | 0.00 | 2.97c | 0.56a | 0.00 | 8.99d | 1.82b | 0.00 | 1.50b | 0.96ab | 0.00 | 9.61d | 1.38b | 0.00 | 9.09d | 1.79b |
| Ethyl-3-hydroxybutyrate | 28.92 | 0.00 | 10.27e | 7.08d | 0.00 | 11.15e | 7.21d | 0.00 | 2.98c | 0.00 | 0.00 | 2.81c | 0.00 | 0.00 | 8.60de | 1.97b | 0.00 | 0.00 | 0.89a | 0.00 | 0.00 | 1.49ab | 0.00 | 0.00 | 1.89b |
| Pentanoic acid 2-hydroxy-4-methyl-ethylester | 30.00 | 0.00 | 16.83f | 7.21c | 0.00 | 5.16b | 7.85c | 0.00 | 10.45d | 12.49e | 0.00 | 9.99d | 13.15e | 0.00 | 6.92c | 15.19e | 0.00 | 3.69a | 7.21c | 0.00 | 6.78c | 15.53e | 0.00 | 6.77c | 15.15e |
| Decanoic acid methylester | 32.95 | 0.00 | 4.10c | 2.00b | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.52a | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 | 0.68a | 0.00 | 0.00 | 0.49a |
| Ethyl decanoate | 35.77 | 0.00 | 5.18c | 1.74b | 0.00 | 1.42b | 0.36a | 0.00 | 1.45b | 1.46b | 0.00 | 1.24b | 1.51b | 0.00 | 1.74b | 5.01c | 0.00 | 1.79b | 2.38b | 0.00 | 1.96b | 4.78c | 0.00 | 1.86b | 5.02c |
| Ethyl benzoate | 36.74 | 0.00 | 5.30bc | 4.81b | 0.00 | 12.38d | 3.86b | 0.00 | 3.89b | 5.87c | 0.00 | 3.92b | 5.71bc | 0.00 | 2.45a | 5.63c | 0.00 | 1.54a | 1.99a | 0.00 | 2.71a | 5.29bc | 0.00 | 2.41a | 5.86c |
| eAcetic acid, 2 phenylethyl | 43.01 | 0.00 | 3.04c | 1.83b | 0.00 | 8.72d | 2.31b | 0.00 | 0.99a | 2.54bc | 0.00 | 1.05a | 2.45bc | 0.00 | 1.65b | 3.98c | 0.00 | 0.96a | 1.75b | 0.00 | 1.85b | 3.99c | 0.00 | 1.72b | 4.14c |
| Methyl Hydrocinnamate | 45.91 | 0.00 | 19.98d | 4.89b | 0.00 | 0.00 | 7.16bc | 0.00 | 10.34c | 13.69d | 0.00 | 10.58c | 13.63d | 0.00 | 10.69c | 4.82b | 0.00 | 5.65b | 2.13a | 0.00 | 10.74c | 4.87b | 0.00 | 10.36c | 4.39b |
| Ethyl dodecanoate | 46.20 | 0.00 | 15.03bc | 0.30a | 0.00 | 9.63b | 0.51a | 0.00 | 10.45b | 1.32a | 0.00 | 10.75b | 1.41a | 0.00 | 1.06a | 20.23c | 0.00 | 0.80a | 8.96b | 0.00 | 1.32a | 20.64c | 0.00 | 1.12a | 21.03c |
| Ethyl Hydrocinnamate | 48.97 | 0.00 | 82.16d | 19.19a | 0.00 | 27.12ab | 16.98a | 0.00 | 98.36d | 99.11d | 0.00 | 101.25e | 91.84de | 0.00 | 64.31c | 32.59b | 0.00 | 39.41b | 19.61a | 0.00 | 66.21c | 38.99b | 0.00 | 66.86c | 38.52b |
| Aldehides | 213.48 | 113.96 | 28.62 | 104.29 | 32.79 | 75.99 | 82.71 | 55.02 | 31.62 | 82.85 | 55.29 | 32.38 | 166.44 | 46.50 | 76.45 | 165.87 | 48.18 | 52.66 | 168.02 | 74.49 | 75.31 | 165.79 | 44.82 | 75.50 | |
| Octanal | 14.81 | 19.20e | 19.85e | 2.85a | 11.85d | 4.17b | 5.89bc | 8.34c | 13.99d | 4.63b | 8.17c | 14.02de | 4.83b | 17.12e | 6.09bc | 10.23d | 17.45e | 7.52c | 5.21b | 16.95e | 12.28d | 9.96d | 16.98e | 5.48b | 10.32d |
| Nonanal | 20.78 | 86.98g | 27.01d | 11.98a | 43.92e | 11.01a | 32.18d | 37.23de | 20.25c | 10.43a | 37.41de | 20.28c | 10.79a | 71.23f | 15.21b | 25.96cd | 70.84f | 15.48b | 19.85c | 69.82f | 32.11d | 25.63cd | 70.94f | 15.02b | 26.41cd |
| 3-Octanal | 21.64 | 0.00 | 2.04a | 5.21b | 0.00 | 1.74a | 1.89a | 0.00 | 2.05a | 0.00 | 0.00 | 2.10a | 0.00 | 0.00 | 2.21a | 2.49a | 0.00 | 2.15a | 2.56a | 0.00 | 2.01a | 2.06a | 0.00 | 2.07a | 2.30a |
| Decanal | 26.85 | 107.30h | 41.21ef | 4.56a | 47.52f | 6.87b | 21.02d | 35.74e | 6.45b | 4.91a | 35.76e | 6.58b | 5.01a | 73.24g | 10.85c | 21.56d | 72.61g | 10.78c | 10.11c | 76.23g | 16.57cd | 21.54d | 73.01g | 10.20c | 19.99d |
| Benzaldehyde | 28.08 | 0.00 | 23.85e | 4.02b | 1.00a | 9.00c | 15.01d | 1.40a | 12.27c | 11.65c | 1.51a | 12.31c | 11.75c | 4.85b | 12.14c | 16.21d | 4.96b | 12.25c | 14.93d | 5.02b | 11.52c | 16.12d | 4.86b | 12.05c | 16.48d |
| Phenols | 0.00 | 202.76 | 181.60 | 0.00 | 129.26 | 255.00 | 0.00 | 9.85 | 52.39 | 0.00 | 9.99 | 52.58 | 0.00 | 148.47 | 412.65 | 0.00 | 116.02 | 395.65 | 0.00 | 123.91 | 376.73 | 0.00 | 126.67 | 374.95 | |
| Guaiacol | 47.25 | 0.00 | 16.93a | 0.00 | 0.00 | 0.00 | 31.08b | 0.00 | 0.00 | 11.84a | 0.00 | 0.00 | 12.01a | 0.00 | 61.02c | 70.25d | 0.00 | 57.16c | 63.55c | 0.00 | 64.13c | 54.23c | 0.00 | 66.84cd | 55.01c |
| Creosol (Homoguaiacol) | 52.57 | 0.00 | 185.23f | 175.28f | 0.00 | 116.01e | 205.83f | 0.00 | 3.65a | 32.57c | 0.00 | 3.89a | 32.41c | 0.00 | 58.62d | 301.25g | 0.00 | 17.89b | 292.14g | 0.00 | 18.30b | 284.60g | 0.00 | 18.76b | 281.52g |
| Phenol | 55.36 | 0.00 | 0.60a | 1.96a | 0.00 | 1.41c | 4.02b | 0.00 | 0.59a | 1.01a | 0.00 | 0.63a | 1.04a | 0.00 | 6.98bc | 10.21c | 0.00 | 5.69b | 9.81c | 0.00 | 5.12b | 9.78c | 0.00 | 5.05b | 9.46c |
| 4-Ethyl phenol | 63.20 | 0.00 | 0.00 | 4.36a | 0.00 | 11.84b | 14.07b | 0.00 | 5.61a | 6.97a | 0.00 | 5.47a | 7.12a | 0.00 | 21.85c | 30.94d | 0.00 | 35.28e | 30.15d | 0.00 | 36.36e | 28.12d | 0.00 | 36.02e | 28.96d |
| Total | 232.68 | 1483.79 | 1044.99 | 152.61 | 1067.93 | 1368.78 | 112.11 | 1522.46 | 1765.60 | 112.86 | 1545.63 | 1757.31 | 234.15 | 1701.07 | 3420.27 | 227.33 | 1530.68 | 3062.18 | 237.51 | 1663.51 | 3194.42 | 229.84 | 1546.72 | 3184.08 | |
a–g for each compound different superscript letters in the same raw are significantly different (P < 0.05).