Table 2.
Composition and peroxidation analysis of thermally processed SOs
| Heating temperature, °C | 22.5 | 45 | 90 | 180 |
|---|---|---|---|---|
| Time heated, h1 | 0 | 288 | 72 | 6 |
| FA, % of total fat2,3 | ||||
| C8:0, caprylic | ND | ND | ND | 0.07 |
| C16:0, palmitic | 10.69 | 10.74 | 11.70 | 11.21 |
| C16:1, palmitoleic | 0.09 | 0.08 | 0.09 | 0.08 |
| C17:0, margaric | 0.10 | 0.10 | 0.11 | 0.10 |
| C18:0, stearic | 4.19 | 4.13 | 4.52 | 4.42 |
| C18:1, oleic | 23.46 | 23.49 | 25.15 | 24.26 |
| C18:2, linoleic | 53.07 | 52.86 | 50.79 | 51.65 |
| C18:3, linolenic | 7.14 | 7.15 | 6.14 | 6.43 |
| C19:0, nonadecanoic | 0.26 | 0.25 | 0.23 | 0.35 |
| C20:0, arachidic | 0.32 | 0.32 | 0.35 | 0.34 |
| C20:1, gadoleic | 0.18 | 0.19 | 0.20 | 0.30 |
| C22:0, behenic | 0.35 | 0.35 | 0.49 | 0.41 |
| C24:0, lignoceric | ND | 0.12 | ND | 0.13 |
| Other FA | 0.15 | 0.22 | 0.23 | 0.27 |
| UFA:SFA | 5.28 | 5.23 | 4.73 | 4.88 |
| IV4 | 131 | 131 | 126 | 127 |
| FFA, %2 | 0.10 | 0.10 | 0.46 | 0.14 |
| Free glycerin, %2 | 1.04 | 3.72 | 0.82 | 0.82 |
| Moisture, % | 0.02 | 0.02 | 0.04 | 0.04 |
| Insoluble impurities, % | 0.02 | 0.04 | 0.04 | 0.04 |
| Unsaponifiable matter, % | 0.51 | 0.39 | 0.41 | 0.47 |
| Oxidized FA, %2 | 3.0 | 2.8 | 2.5 | 1.9 |
| OSI @ 110 C, h2 | 6.65 | 4.65 | 2.70 | 3.65 |
| AnV2,5 | 1.11 | 1.33 | 121 | 165 |
| PV, mEq/kg2 | 2.0 | 17.4 | 123.6 | 19.4 |
| Polar compounds, %2 | 3.61 | 3.28 | 20.25 | 11.58 |
| PTAG6, % | ND | ND | 3.16 | 3.10 |
| TBA value2,5 | 0.14 | 1.14 | 0.14 | 0.14 |
| Aldehydes, mg/kg7 | ||||
| DDE | 2.07 | 1.90 | 912.15 | 915.49 |
| HNE | 0.66 | 1.49 | 170.48 | 82.80 |
| Acrolein | 6.15 | 6.06 | 27.12 | 44.60 |
| 2-Decenal | 0.16 | 0.19 | 55.21 | 81.60 |
| 2,4-Heptadienal | 0.47 | 1.19 | 268.62 | 151.65 |
| 2-Heptenal | 2.33 | 1.82 | 254.48 | 90.68 |
| Hexanal | 2.01 | 2.02 | 33.69 | 6.28 |
| 2-Octenal | 0.40 | 0.67 | 212.60 | 51.96 |
| Pentanal | 5.36 | 1.05 | 10.76 | 2.84 |
| 2,4-Undecadienal | 0.06 | 0.07 | 43.73 | 53.34 |
| 2-Undecenal | 0.19 | 0.19 | 50.29 | 110.38 |
| Ratio8 | 0.12 | 0.21 | 0.58 | 1.14 |
| TOC, mg/kg2 | 1,328 | 1,331 | 94 | 798 |
| Alpha | 98 | 97 | <10 | <10 |
| Beta | <10 | <10 | <10 | <10 |
| Delta | 196 | 209 | 15 | 169 |
| Gamma | 1,034 | 1,025 | 79 | 629 |
AnV, p-anisidine value; DDE, 2,4-decadienal; FA, fatty acid; FFA, free fatty acids; HNE, 4-hydroxynonenal; IV, iodine value; ND, not detected; OSI, oil stability index; PTAG, polymerized tryacylglycerides; PV, peroxide value; TBA, thiobarbituric acid; TOC, tocopherol; UFA:SFA, unsaturated:saturated fatty acid ratio.
1Thermally processed oils had constant air flow rate at 15 L/min.
2Analyzed by Barrow-Agee, Memphis, TN.
3No other FA were detected besides those listed.
4IVs were calculated using the FA profile data following the equation: VI = (16:1 × 0.95) + (18:1 × 0.86) + (18:2 × 1.732) + (18:3 × 2.616) + (20:1 × 0.795) + (20:2 × 1.57) + (20:3 × 2.38) + (20:4 × 3.19) + (20:5 × 4.01) + 22:4 × 2.93) + (22:5 × 3.68) + (22:6 × 4.64); Meadus et al. (2010).
5There are no units for AnV or TBA value.
6Analyzed by the USDA-ARS, Peoria, IL.
7Analyzed by University of Minnesota, St. Paul, MN.
8Ratio of 2-decenal, 2,4-hydroxynonenal, 2,4-undecadienal, and 2-undecenal as a percent of total aldehydes to acrolein, 2,4-heptadienal, and 2-heptenal as a percent of total aldehydes; Wang et al. (2016).