Table 3.
Effects of three different pretreatments on some quality characteristics of rapeseed oil
| Pretreatment | Untreated | Roasted | Microwave | Steam explosion |
|---|---|---|---|---|
| Oil yield (%) | 69.26 ± 2.83c | 74.77 ± 2.01b | 75.47 ± 1.98b | 80.11 ± 2.79a |
| AV (mg/g oil) | 1.15 ± 0.01b | 1.56 ± 0.00a | 1.45 ± 0.22a | 1.43 ± 0.12a |
| POV (meq. O2/kg oil) | 0.65 ± 0.07c | 0.75 ± 0.03ab | 0.78 ± 0.02a | 0.72 ± 0.01ab |
| Phytosterols (mg/kg oil) | 6,008.49 ± 90.51c | 6,245.76 ± 98.99bc | 6,359.28 ± 113.14ab | 6,622.65 ± 127.28a |
| Tocopherols (mg/kg oil) | 635.24 ± 10.03c | 654.84 ± 14.28bc | 678.52 ± 12.25ab | 686.67 ± 12.84a |
| DPPH (μmol/100 g oil) | 16.52 ± 1.18d | 169.49 ± 2.96c | 240.46 ± 3.87b | 270.12 ± 1.64a |
| FRAP (μmol/100 g oil) | 20.56 ± 0.78d | 175.26 ± 5.47c | 278.81 ± 4.94b | 305.12 ± 5.84a |
| OIT (hr) | 10.62 ± 0.08d | 15.23 ± 0.32a | 13.86 ± 0.16c | 14.58 ± 0.45b |
Different letters in a row mean significant difference at the 5% level.
AV, POV, DPPH, FRAP, OIT, respectively, represented acid value, peroxide value, DPPH free radical scavenging ability, ferric ion reducing antioxidant power, and oxidation induction time.
Roasted, microwave, steam explosion pretreatment methods, respectively, represented 180 ℃ for 15 min, 800 W for 6 min at a frequency of 2,450 MHz and steam explosion pressure at 1.0 MPa.