# The Influence of Storage Conditions of Cold-Pressed Rapeseed Oil on Its Quality Parameters
## 3 Results and Discussion
The storage time is also essential because, as demonstrated over three months, the AV may even increase twice, with additional storage conditions remaining unchanged. Still, the rate of these changes depends mainly on the effect of temperature, as indicated by [PERSON] et al. [35]. Moreover, [PERSON] et al. showed that the AV of storage cold-pressed rapeseed oil changes insignificantly during storage in a nitrogen atmosphere [36]. The last quality parameter to be examined was radical scavenging activity, which is understood as an increase in the activity of the ABTS**+** radical during oil storage. Research by [PERSON] et al. [37] proved that as the temperature of storage of vegetable oils increases, their %RSA decreases, which was confirmed in this study. Samples stored at 4 \({}^{\circ}\)C show much lower oxidative activity of the ABTS**+** radical. Furthermore, [PERSON] et al. [38] showed that regardless of storage conditions, the %RSA of samples decreases with increasing storage time. This confirms the results obtained in this work. In order to clearly determine which factors mainly influence the changes in the physicochemical properties of oils during storage, a principal component analysis (PCA) was performed on the samples shown in Figure 2a,b. The statistical analysis confirmed that two factors mainly influence the change in the physicochemical parameters of rapeseed oil during storage. The first is the storage temperature (blue field in Figure 2b), because the higher the temperature of the stored samples, the faster the degradation of the components dissolved in the oil. The second important factor is storage time (brown fields in Figure 2b). The analysis showed that samples stored in the same conditions, but for a shorter period, showed significantly better properties than samples stored for longer durations. Other factors affecting the change in oil parameters during storage are irrelevant. [PERSON] [2] confirmed the obtained results and indicated that they are significant, especially for oils not subject to refining. To maximize the freshness and nutritional properties of oils, they should be stored in cool places as soon as possible after their production date. In turn, [PERSON] et al. [39] indicated the production process parameters as another factor determining the rate of autoxidation of vegetable oils. They showed that cold-pressed and sedimented oil decompose much more slowly than oils pressed at elevated temperatures. [PERSON] et al. [15] suggested adding natural antioxidants (e.g., plant extracts), which would slow down the autoxidation processes of oils and give them innovative sensory properties. Further research on changes in the physicochemical properties of oils during storage should focus on the correlation between changes in the oxidative stability of the oil and changes in its fatty acid profile. [PERSON] et al. [40] showed that the higher oxidative stability of the sample may have been caused by a greater degree of degradation of unsaturated fatty acids. However, [PERSON] et al. [21] showed that a higher content of unsaturated fatty acids in oils made them more susceptible to autoxidation and free radicals with the ABTS method. Moreover, they showed a correlation between oxidative stability and the content of \(\alpha\)-linolenic fatty acid. The statistical analysis confirmed that two factors mainly influence the change in the physicochemical parameters of rapeseed oil during storage. The first is the storage temperature (blue field on the right graph), because the higher the temperature of the stored samples, the faster the degradation of the components dissolved in the oil. The second important factor is storage time (brown fields on the right graph). The analysis demonstrated that samples stored in the same conditions, but for a shorter period of time,showed significantly better properties than samples stored for longer periods. Other factors affecting the change in oil parameters during storage are irrelevant.