Table 6.
Fatty acids composition of onion seeds as affected by bulb planting time (n = 3 ± SD).
| Fatty Acid | 20 December | 10 January | 31 January | 21 February | ||
|---|---|---|---|---|---|---|
| Saturated | ||||||
| Lauric | 12:0 | 0.03 ± 0.004 | 0.03 ± 0.004 | 0.02 ± 0.002 | 0.02 ± 0.002 | n.s. |
| Miristic | 14:0 | 0.13 ± 0.02 b | 0.13 ± 0.02 b | 0.14 ± 0.02 a,b | 0.16 ± 0.02 a | |
| Pentadecanoic | 15:0 | 0.05 ± 0.01 b | 0.06 ± 0.02 a,b | 0.06 ± 0.01 a,b | 0.07 ± 0.01 a | |
| Pentadecenic | 15:1 | 0.02 ± 0.003 | 0.02 ± 0.003 | 0.02 ± 0.001 | 0.03 ± 0.003 | n.s. |
| Iso-esadecanoic | 16:0 i | 0.02 ± 0.002 | 0.02 ± 0.002 | 0.02 ± 0.002 | 0.02 ± 0.002 | n.s. |
| Palmitic | 16:0 | 6.84 ± 0.41 c | 7.67 ± 0.40 b | 8.10 ± 0.38 a,b | 8.48 ± 0.35 a | |
| Margaric | 17:0 | 0.04 ± 0.006 | 0.05 ± 0.004 | 0.05 ± 0.006 | 0.05 ± 0.004 | n.s. |
| Stearic | 18:0 | 1.57 ± 0.12 b | 1.78 ± 0.17 a,b | 2.02 ± 0.24 a | 1.97 ± 0.21 a | |
| Iso-ottadecanoic | 18:0 i | 0.14 ± 0.012 a | 0.13 ± 0.006 a,b | 0.12 ± 0.010 b | 0.09 ± 0.004 c | |
| Arachic | 20:0 | 0.22 ± 0.03 c | 0.30 ± 0.03 b | 0.38 ± 0.03 a | 0.40 ± 0.04 a | |
| Beeric | 22:0 | 0.14 ± 0.01 a | 0.13 ± 0.01 a,b | 0.13 ± 0.01 a,b | 0.12 ± 0.01 b | |
| Lignoceric | 24:0 | 0.04 ± 0.004 | 0.05 ± 0.004 | 0.05 ± 0.004 | 0.04 ± 0.003 | n.s. |
| Total | 9.24 ± 0.62 c | 10.37 ± 0.64 b | 11.11 ± 0.47 a,b | 11.45 ± 0.51 a | ||
| Monounsaturated | ||||||
| Sapienic | 16:1 6-cis | 0.07 ± 0.01 | 0.08 ± 0.01 | 0.08 ± 0.01 | 0.08 ± 0.01 | n.s. |
| Palmitoleic | 16:1 9-cis | 0.15 ± 0.02 c | 0.17 ± 0.02 b,c | 0.18 ± 0.02 a,b | 0.20 ± 0.02 a | |
| Eptadecenoic | 17:1 | 0.03 ± 0.003 | 0.04 ± 0.003 | 0.04 ± 0.003 | 0.04 ± 0.003 | n.s. |
| Oleic | 18:1 9-cis | 30.8 ± 1.58 a | 27.7 ± 1.71 b | 25.8 ± 1.65 b,c | 23.4 ± 2.23 c | |
| Vaccenic | 18:1 11-trans | 1.28 ± 0.12 | 1.30 ± 0.12 | 1.29 ± 0.10 | 1.30 ± 0.10 | n.s. |
| Gondoic | 20:1 11-cis | 0.41 ± 0.10 | 0.44 ± 0.06 | 0.43 ± 0.08 | 0.42 ± 0.10 | n.s. |
| Total | 32.74 ± 1.53 a | 29.76 ± 1.70 b | 27.82 ± 1.70 b,c | 25.44 ± 2.12 c | ||
| Polyunsaturated | ||||||
| Iso-ottadecadienoic | 18:2 i | 0.07 ± 0.01 | 0.08 ± 0.01 | 0.07 ± 0.01 | 0.07 ± 0.02 | n.s. |
| Linoleic | 18:2 | 55.6 ± 2.48 b | 57.5 ± 2.51 a,b | 59.0 ± 2.86 a,b | 61.1 ± 2.62 a | |
| α-linolenic | 18:3 | 0.12 ± 0.01 | 0.11 ± 0.01 | 0.10 ± 0.02 | 0.12 ± 0.02 | n.s. |
| γ-linolenic | 18:3 | 0.03 ± 0.01 | 0.04 ± 0.01 | 0.02 ± 0.01 | 0.03 ± 0.01 | n.s. |
| Punicic (isomers sum) | ∑ 18:3 | 1.94 ± 0.15 a | 1.84 ± 0.13 a | 1.54 ± 0.14 b | 1.50 ± 0.16 b | |
| Eicosatrienoic | 20:3 | 0.03 ± 0.006 a | 0.03 ± 0.006 a | 0.01 ± 0.005 b | 0.01 ± 0.005 b | |
| Arachidonic | 20:4 | 0.25 ± 0.02 | 0.27 ± 0.03 | 0.29 ± 0.02 | 0.30 ± 0.02 | n.s. |
| Total | 58.02 ± 2.63 b | 59.87 ± 2.37 a,b | 61.07 ± 2.72 a,b | 63.11 ± 2.54 a |
Along each line: n.s. not statistically significant; means followed by different letters are significantly different according to the Duncan test at p ≤ 0.05. Mean values ± standard deviations have been reported for the main effects of the experimental factors.