## 3 Results and Discussion
### Oxidative Stability of Analysed Oils  
Oxidative stability is an important quality characteristic of edible oils that determines their resistance to oxidation. Due to the fact that it depends mainly on the composition of fatty acids, oils with a high content of polyunsaturated fatty acids are the least stable. Moreover, it is significantly affected by the presence of pro- and antioxidant substances. The oxidation induction time of the tested oils varied in terms of the type of oil and the temperature used in the Rancimat test, ranging from 90 to 150 \({}^{\circ}\)C (Table 4).  
The induction time for oils at 120 \({}^{\circ}\)C ranged from 1.07 h to 28.92 h. Coriander seed oil proved to be the most stable oil, with an induction time of 28.92 h. An equally high value of 14.6 h in the Rancimat test at 110 \({}^{\circ}\)C was also obtained by [PERSON] and [PERSON] [54]. The study of [PERSON] et al. [24] also confirms the low susceptibility to oxidation of coriander seed oil, as the induction time they determined at 110 \({}^{\circ}\)C was equal to 27.3 h. The high oxidative stability of this oil may be determined by a high content (>70%) of monounsaturated petroselinic acid, which is oxidised more easily than polyenoic acids. It is knownthat linoleic acid oxidises from 10 to 40 times faster than oleic acid, whereas \(\alpha\)-linolenic acid oxidises 2-4 times faster than linoleic acid [55]. In addition, coriander seed oil was characterised by a high content of antioxidant components, such as tocopherols, sterols, or carotenoids, which affects the delay of the oxidation process [56]. Moreover, the main component (81.6%) of coriander essential oil--linalool--inhibits lipid peroxidation [57].  
Basil seed oil had the shortest induction time at 120 \({}^{\circ}\)C of 1.07 h. When measuring the oxidative stability at 110 \({}^{\circ}\)C, [PERSON] et al. [58] recorded 1.39 h. The low oxidation resistance of basil seed oil is the high content of unsaturated fatty acids, especially polyunsaturatedated acids. The fatty acid profile is dominated by \(\alpha\)-linolenic acid (52.10%) and linoleic acid (20.16%), with the total content reaching up to 70%. The remaining oils (dill seed, fenugreek seed, parsley seed, watercress seed, and tomato seed) were characterised by oxidative stability at a similar level, with induction times ranging from 2.1 to 3.6 h (Table 4).  
Of the above, dill seed oil had the longest oxidation induction time at 120 \({}^{\circ}\)C--3.6 h. A 10-degree lower temperature increased this time to 7.12 h. According to [PERSON]'s rule, a 10 K increase in temperature results in a 2-4 fold increase in reaction rate; so, the formation time of oxidation products at 110 \({}^{\circ}\)C was much longer. [PERSON] et al. [44] also obtained 7 h at 110 \({}^{\circ}\)C. Parsley seed oil had lower oxidative stability than dill seed oil. The oxidation induction time at 120 \({}^{\circ}\)C was 2.91 h. However, at 100 \({}^{\circ}\)C, the time increased to almost 13 h. The relatively good oxidative stability of parsley seed oil may be determined by the presence of a large amount of monounsaturated petroselinic acid, the content of which reaches over 70% [40]. The oxidation induction time obtained for fenugreek seed oil and tomato seed oil at 120 \({}^{\circ}\)C was short and was 2.24 and 2.10 h, respectively. The fatty acid profile of fenugreek seed oil is dominated by linoleic acid (C18:2), with more than half of the total acids, which may cause low stability [59]. Analysing the oxidative stability at 120 \({}^{\circ}\)C for FO, [PERSON] et al. [60] reported an induction time of 2.85 h, which they also explained by the high content of PUFA acids. [PERSON] et al. [61], investigating the stability of oils from different non-conventional feedstocks at 110 \({}^{\circ}\)C, obtained 25.4 h for tomato seed oil.