## 3 Results
### Antioxidant Activity  
The formation of primary lipid oxidation products throughout 24 days of storage of the samples was measured using the amount of PV. The effect of RGEO, BHA, and BHT on PV changes in cold-pressed sunflower oil lipids has been shown in Table 3. The PV of samples treated with RGEO, after 8 days and 16 days of incubation, were lower than the values of the control sample and samples treated with BHA and BHT, with a high significance level (\(p<0.001\)). After 12 days of incubation, the PV of the sample treated with RGEO was lower than the values of the control sample and sample containing BHA but higher than the values of the sample containing BHT with high significance in all cases (\(p<0.01\)). Finally, after 20 days and 24 days of incubation, the PV of the sample treated with RGEO was significantly lower than the control sample values (\(p<0.001\)) and significantly higher than the samples treated with BHA and BHT (\(p<0.001\)). TBA value has been extensively applied to evaluate the degree of lipid oxidation. TBA reactive substances are reckoning the second stage auto-oxidation, during which peroxides are oxidized to aldehyde and ketone [51]. The changes in TBA value of different treatment samples during 24 days are shown in Table 4. Generally, the values of samples treated with RGEO were closer to BHA values in the case of TBA measurements. From day 0 through day 20, the TBA values of samples treated with RGEO were higher than those of samples treated with BHA, but the difference was not significantly different, with only one exception, day 4. However, after 24 days of incubation, the values of TBA were lower for samples treated with RGEO but not significantly different according to [PERSON]'s test (\(p=0.32\)). Regarding the TBA values of samples treated with BHT, samples treated with RGEO were significantly higher after 4 through 20 days of incubation. \begin{table}
\begin{tabular}{l l l l} \hline
**No** & **Compounds** & **KI a** & **\%** \\ \hline
32. & Geranyl isovalerate & 1663 & 0.32 \\
33. & alpha-Eudesmol & 1669 & 0.38 \\
34. & 1,2,3,3a,4,9,10,10a-Octahydrobenzo[f]azulene & 1681 & 0.40 \\
35. & Corymbolone & 1743 & 0.13 \\
36. & Methoxsalen & 1977 & 0.16 \\
37. & Bergaptene & 1995 & 0.56 \\ \hline \multicolumn{4}{c}{Total:} & 98.68 \\ \hline \end{tabular}  
* Retention indices (RIs) calculated upon the calibration curve of alkane C\({}_{8}\)–C\({}_{20}\) standard injected and analyzed in the same conditions as RGEO; tr. (trace) \(<0.05\).  
\end{table} 
Table 2: _Cont._ \begin{table}
\begin{tabular}{c c c c c} \hline  & \multicolumn{3}{c}{**PV (meq of Oxygen kg\({}^{-1}\))**} \\ \hline
**Storage Time (Days)** & **Control Sample** & **BHT** & **BHA** & **RGEO** \\ \hline
**0 days** & 1.97 \(\pm\) 0.05 bc & 1.88 \(\pm\) 0.04)a & 1.93 \(\pm\) 0.06 ab & 2 \(\pm\) 0.04 c \\ \hline
**4 days** & 3.1 \(\pm\) 0.06 a & 2.98 \(\pm\) 0.06 c & 3.21 \(\pm\) 0.06 b & 3.13 \(\pm\) 0.09 ab \\ \hline
**8 days** & 5.67 \(\pm\) 0.07 a & 4.28 \(\pm\) 0.04 b & 5.9 \(\pm\) 0.06 c & 4.01 \(\pm\) 0.05 d \\ \hline
**12 days** & 7.7 \(\pm\) 0.05 a & 5.91 \(\pm\) 0.06 b & 7.06 \(\pm\) 0.07 c & 6.56 \(\pm\) 0.08 d \\ \hline
**16 days** & 9.73 \(\pm\) 0.07 a & 8.66 \(\pm\) 0.08 b & 8.68 \(\pm\) 0.04 b & 8.19 \(\pm\) 0.05 c \\ \hline
**20 days** & 12.12 \(\pm\) 0.05 a & 9.58 \(\pm\) 0.03 b & 9.82 \(\pm\) 0.06 c & 9.95 \(\pm\) 0.06 d \\ \hline
**24 days** & 15.91 \(\pm\) 0.07 a & 10.03 \(\pm\) 0.05 b & 10.11 \(\pm\) 0.08 b & 11.49 \(\pm\) 0.08 c \\ \hline \end{tabular}  
* Values with different superscripts are significantly different (\(p<0.05\)) according to Tukey test; each value is the Mean \(\pm\) SD.  
\end{table} 
Table 3: The antioxidant effects of RGEO, BHA, and BHT in terms of peroxide values (meq of oxygen kg\({}^{-1}\)). Antioxidants interact with 1,1-diphenyl-2-picrylhydrazyl radical, a stable free radical, and transform it into 1,1-diphenyl-2-picrylhydrazine. The degree of discoloration demonstrates the radical scavenging potential or the hydrogen-donating ability of the compounds [52].