## 3 Results and Discussion  
### Analysed Oils' Initial Qualities  
The first step of the oil analysis was to evaluate the oils' initial qualities. According to the Codex Alimentarius standard, the permitted value of the acid value (AV), which is used to determine the amount of free fatty acids in cold-pressed oils, should not exceed 4.0 mg KOH/g oil. The AV values of the tested oils ranged from 0.34 (dill seed oil) to 4.61 mg KOH/g oil (coriander seed oil) (Table 1). [PERSON] and [PERSON] [17] mentioned a lower value (2.84 mg KOH/g oil) in their study on the coriander seed oil, thus complying with the standard. The elevated AV of oils may be due to the quality of the raw material used. Damaged, too wet, or contaminated raw material determines intensive hydrolytic changes. Pressing conditions are also an important factor affecting the quality of the final product [18; 19]. The peroxide values (PV) obtained in the oil analysis ranged from 3.41 to 44.91 mEq O\({}_{2}\)/kg. Of the oils tested, only four met the requirements for the permitted content of primary oxidation products in oils (15 mEq O\({}_{2}\)/kg): PO, FO, and CO with 11.73, 9.98, and 9.34 mEq O\({}_{2}\)/kg, respectively. The highest PV was determined in TO with 44.91 mEq O2/kg. The values recorded by other researchers were much lower than the ones obtained in our study. [PERSON] et al. [20], studying this parameter in TO, obtained a PV equal to 9.3 mEq O\({}_{2}\)/kg, and a lower peroxide value (3.93 mEq O\({}_{2}\)/kg) was obtained by [PERSON] et al. [21]. The discrepancy between the results of these researchers may be due to the fact that they determined PV in fresh oil, i.e., immediately after pressing, which significantly affects the low degree of oil oxidation. A high PV value can be caused by a long period of oil storage and exposure to undesirable external factors: high temperature, oxygen, and light. An additional factor that accelerated the degradation transformations in TO is the high content of PUFAs (over 60%), mainly linoleic acid, which is oxidised much faster than MUFAs. The \(p\)-anisidine value (\(p\)-AnV), which determines the content of secondary oxidation products, took values from 2.05 to 12.01 in tested oils. In the case of cold-pressed oils, there are no designated \(p\)-AnV limits, but it is assumed that they should have lower values than their refined counterparts [22]. According to the PN-A-86908:2000 standard, the \(p\)-AnV of refined oils should not exceed the value of 8. The oil exceeding the \(p\)-AnV standard for refined oils was coriander seed oil (12.01), indicating an increased content of secondary oxidation products. [PERSON] et al. [23], studying the \(p\)-AnV of coriander seed oil, obtained a value of 3.1; a lower value, amounting to 0.46, was achieved by [PERSON] et al. [24]. Relatively high \(p\)-AnVs, of 6.82 and 6.55, respectively, were also achieved for TO and PO. For tomato seed oil, [PERSON] [25] obtained \(p\)-AnV values ranging from 7.48 to 17.32, depending on the solvent used for extraction. The \(p\)-AnV values presented in the literature differ, which may be due to different methods of oil extraction or an advanced degree of oxidation and the breakdown of peroxides (primary oxidation products) to carbonyl compounds (secondary oxidation products) under the influence of heating the raw material or oil in the technological process [26]. Lower values of \(p\)-AnV characterised the remaining oils. The lowest value, equal to 2.05, was characteristic of WCO. This value was similar to the result of [PERSON] et al. [27], who tested the \(p\)-AnV of cress seed oil and obtained a value of 2.17. The total degree of the oils' oxidation was indicated by the TOTOX fat oxidation index, which was calculated from the \(p\)-AnV and PV of the oils. The TOTOX index in this study took values in a wide range from 9.65 to 95.92, and only basil seed oil met the criteria of good quality, as the value of the tested parameter did not exceed 10 [28].