## 3 Results and Discussion
### Physicochemical Characteristics
for their color [27; 64; 65; 66]. According to the results (Table 3 and Figure 5), it is observed that the oil produced from CO\({}_{2}\)-processed olives had the highest concentration in both these bioactive substances. In Figure 5, the absorption spectra obtained for chlorophylls and carotenoids in different olive oils are presented. The oil produced from control olives appeared to be very poor in these compounds. These results were also verified by the colorimetry technique. Total pigments were measured for the oil produced from the CO\({}_{2}\)-processed sample and were found to be 6.021 \(\pm\) 0.056 mg/Kg as opposed to the commercial oil sample containing 3.493 \(\pm\) 0.097 mg/Kg and the oil produced from the control sample (0.782 \(\pm\) 0.015 mg/Kg). Subsequently, the oils' total polyphenol content was determined. The total polyphenols for the oil produced from the CO\({}_{2}\)-processed olives sample were 209.09 \(\pm\) 18.86 mg of gallic acid equivalents (GAE)/Kg, while for the commercial oil sample was 132.20 \(\pm\) 8.68 mg GAE/Kg. The oil produced from the control sample was found to have a low content in total polyphenols and specifically 44.52 \(\pm\) 18.36 mg GAE/Kg. In addition, the determination of \(\alpha\)-tocopherol content of the samples was carried out. The concentration of \(\alpha\)-tocopherol for the oil produced from the CO\({}_{2}\)-processed sample was 180.89 \(\pm\) 22.91 mg/Kg, while for the commercial oil sample was 102.04 \(\pm\) 12.26 mg/Kg. The oil produced from the control sample was found to have a low \(\alpha\)-tocopherol concentration of 32.12 \(\pm\) 5.17 mg/Kg. The Rancinat method was performed to evaluate the oils' susceptibility to oxidation [67; 68]. The oil produced from the CO\({}_{2}\)-processed sample showed an induction period of 13.70 \(\pm\) 0.14 h, while the commercial oil and the oil produced from control olives samples were 6.35 \(\pm\) 0.21 and 3.50 \(\pm\) 0.14 h, respectively. The oxidative stability of the oil deriving from the olives stored under the CO\({}_{2}\) atmosphere was significantly higher (\(p\) < 0.05) compared to the two other samples of olive oils. The fatty acid (FA) profile is shown in Table 4. It is observed that the main FA in all samples was oleic acid (C18:1 cu-9c). There were statistically significant differences (\(p\) < 0.05)  
Figure 5: Absorption spectra obtained for chlorophylls (670 nm) and carotenoids (470 nm) in different olive oils. in the FA profiles between the different samples. More specifically, monounsaturated fatty acids (MUFAs) were found to be 75.54 \(\pm\) 0.42, 73.10 \(\pm\) 0.75, 69.76 \(\pm\) 0.64%, saturated fatty acids (SFAs) found 15.18 \(\pm\) 0.18, 13.10 \(\pm\) 0.09, 17.27 \(\pm\) 0.40% and polyunsaturated fatty acids (PUFAs) found 9.18 \(\pm\) 0.13, 6.02 \(\pm\) 0.09, 12.80 \(\pm\) 0.21% for the commercial oil, oil produced from control olives and oil produced from CO\({}_{2}\)-processed olives, respectively. Based on the results, regarding olive oils, the overall percentage of FAs and their profile is in accordance with the literature [36; 69]. The FAs content of the oils is the primary factor used to establish their quality indices during production, storage, and trading [70]. As a result, the quantity of FAs in oil closely corresponded to the oil's authenticity and quality. All the above results indicate that the oil produced from the CO\({}_{2}\)-processed olive sample had all characteristics rendering it suitable to be labeled as EVOO. In addition, the unique organoleptic characteristics such as the aroma, flavor, and color of the product, the high antioxidant activity, and the high content of bioactive compounds (polyphenols, \(\alpha\)-tocopherol, carotenoids, and chlorophylls) resulted in an innovative olive oil with excellent chemical characteristics and probable beneficial effects on health [14; 65].