Table 1.
Chemical composition of rapeseed oil.
| Pressed Oil |
Refined Oil |
Partially Hydrogenated Oil (IV = 90) | Partially Hydrogenated Oil (IV = 79) | |
|---|---|---|---|---|
| Peroxide value (mEq O2/kg) |
1.00 ± 0.15 a,* | 0.19 ± 0.04 b | 0.20 ± 0.03 b | 0.11 ± 0.02 c |
| Anisidine value | 0.08 ± 0.00 a | 0.26 ± 0.01 b | 5.59 ± 0.22 c | 4.00 ± 0.23 d |
| Acid value (mg KOH/g) |
2.31 ± 0.27 a | 0.15 ± 0.03 b | 0.28 ± 0.03 c | 0.18 ± 0.02 b |
| Total polar components (TPC) (%) | 8.5 ± 1.32 a | 1.5 ± 0.39 b | 7.1 ± 0.62 a | 6.4 ± 1.38 c |
| Iodine value (g I2/100 g of oil) |
118 ± 2.76 a | 118 ± 1.16 a | 90 ± 1.15 b | 79 ± 1.46 c |
| Tocopherols (mg/100 g) | ||||
| α-T | 34.44 ± 0.17 a | 30.54 ± 0.46 b | 27.10 ± 0.41 c | 15.21 ± 0.36 d |
| ᵝ-T | 0.30 ± 0.03 a | 0.14 ± 0.01 b | 0.13 ± 0.02 b | 0.05 ± 0.02 c |
| ᵧ-T | 39.53 ± 0.35 a | 33.57 ± 0.47 b | 31.20 ± 0.65 b | 18.71 ± 0.37 c |
| δ-T | 0.91 ± 0.04 a | 0.67 ± 0.05 a | 0.88 ± 0.17 a | 0.52 ± 0.03 b |
| Total | 75.19 ± 0.31 a | 64.93 ± 0.99 b | 59.32 ± 0.96 c | 34.49 ± 0.38 d |
| Fatty acid composition (%) | ||||
| 16:0 | 4.39 ± 0.04 a | 4.45 ± 0.02 a | 4.77 ± 0.29 a | 5.66 ± 0.69 b |
| 16:1 | 0.21 ± 0.00 a | 0.22 ± 0.01 a | 0.08 ± 0.03 b | 0.08 ± 0.11 b |
| 18:0 | 1.69 ± 0.03 a | 1.70 ± 0.03 a | 4.25 ± 0.24 b | 11.36 ± 0.85 c |
| 18:1 cis | 60.43 ± 0.11 a | 60.13 ± 0.32 a | 53.93 ± 2.47 b | 39.93 ± 1.18 c |
| 18:1 trans | nd ** | nd | 24.63 ± 2.63 a | 33.15 ± 1.16 b |
| 18:2 cis | 18.93 ± 0.10 a | 19.32 ± 0.39 a | 1.00 ± 0.32 b | 0.77 ± 0.06 b |
| 18:2 trans | nd | 0.03 ± 0.00 a | 7.51 ± 1.80 b | 5.01 ± 0.54 c |
| 18:3 cis | 12.24 ± 0.12 a | 11.51 ± 0.07 a | 1.03 ± 0.32 b | 0.60 ± 0.05 b |
| 18:3 trans | 0.02 ± 0.00 a | 0.53 ± 0.08 b | 1.67 ± 0.13 c | 1.29 ± 0.12 d |
| 20:0 | 0.58 ± 0.03 a | 0.58 ± 0.02 a | 0.09 ± 0.00 b | 0.86 ± 0.04 c |
| 22:0 | 0.31 ± 0.02 a | 0.33 ± 0.01 a | 0.36 ± 0.01 a | 0.61 ± 0.04 b |
| 22:1 | 1.20 ± 0.20 a | 1.20 ± 0.14 a | 0.69 ± 0.18 b | 0.67 ± 0.08 b |
Values are means of three determinations ± SD. * Means in the same row followed by different letters indicate significant differences (p < 0.05) between samples of each type of oil. ** nd—not detected. IV—iodine value.