Table 5. Parameters of DPPH˙ disappearance determined by first-order double-exponential model, total radical scavenging activity (RSAT), radical scavenging activity during the first and second steps of reaction (RSA1 and RSA2 respectively) and antioxidant activity of tocopherol isomers involved in different steps of the reaction.
Oil sample |
DPPH˙1 | DPPH˙2 | DPPH˙r | RSAT | RSA1 | RSA2 | Activity | Ratio of activities (B/A) |
||
---|---|---|---|---|---|---|---|---|---|---|
% | A | B | ||||||||
CP1 | 0.376 | 0.365 | 0.246 | 74.07 | 38.08 | 37.02 | 0.060 | 1.473 | 24.51 | |
CP2 | 0.336 | 0.431 | 0.230 | 76.75 | 33.71 | 43.24 | 0.040 | 1.505 | 37.40 | |
RS1 | 0.357 | 0.277 | 0.366 | 63.41 | 35.71 | 27.72 | 0.033 | 0.342 | 10.37 | |
RS2 | 0.294 | 0.338 | 0.368 | 63.21 | 29.40 | 33.82 | 0.065 | 0.159 | 2.46 | |
RS3 | 0.312 | 0.342 | 0.350 | 65.36 | 31.05 | 34.09 | 0.042 | 0.085 | 2.02 | |
RS4 | 0.264 | 0.293 | 0.442 | 55.75 | 26.44 | 29.31 | 0.032 | 0.131 | 4.10 | |
RS5 | 0.290 | 0.297 | 0.410 | 58.69 | 29.08 | 29.77 | 0.047 | 0.125 | 2.65 | |
S1 | 0.659 | 0.124 | 0.222 | 78.32 | 65.59 | 12.34 | 0.101 | 0.025 | 0.25 | |
S2 | 0.553 | 0.273 | 0.177 | 82.54 | 55.10 | 27.22 | 0.255 | 0.045 | 0.18 |
A=activity of γ- and δ-tocopherols, calculated as (0.4·RSA1)/(w(γ-tocopherol)+w(δ-tocopherol)), B=activity of α-tocopherol, calculated as (0.4·RSA2)/w(α-tocopherol). DPPH˙0, DPPH˙t, DPPH˙1, DPPH˙2 and DPPH˙r are the ratios of absorbance at the beginning of the experiment (at time t=0), at time t, steps 1 and 2 and remaining value, respectively