# The Influence of Storage Conditions of Cold-Pressed Rapeseed Oil on Its Quality Parameters
## 3 Results and Discussion  
The filtered rapeseed oil was subjected to preliminary analyses, the results of which are presented in Table 2.  
The results obtained using the described methodology were averaged and converted into percentage changes with respect to the control sample according to the selected \begin{table}
\begin{tabular}{c c} Chlorophylls (mg/kg) & 19.9 \\ Carotenoids (mg/kg) & 83.4 \\ L* [-] & 96.013 \\ a* [-] & \(-\)6.492 \\ b* [-] & 94.563 \\ AV (mg\({}_{\text{KOH}}\)/g) & 1.119 \\ ABTS** (\%RSA) & 1.77 \\ \end{tabular}
\end{table} 
Table 2: Results of preliminary tests of rapeseed oil. parameters during the 3- and 6-month oil storage periods. The test results are collectively presented for each oil sample in Table 3.  
Based on the obtained results, it was found that over time, the content of chlorophyll and carotenoid pigments decreased in cold-pressed rapeseed oil. The decrease in the content of natural dyes after three months was 7 to even 87%, depending on storage conditions, and after six months, from 12 to 97%. The analysis of the results shows that the reduction in the content of natural dyes was mainly influenced by the temperature at which the samples were stored. Higher oil storage temperature causes a faster decomposition of natural dyes, as was confirmed by research conducted by [PERSON] et al. [30]. Factors such as packaging and the presence of air are of secondary importance to the decrease in the content of natural dyes. [PERSON] et al. [31] showed that long-term exposure of oil to highly oxygenated air accelerates the decomposition of natural dyes. However, the amount of oxygenated air was limited in the studies that reflected the actual method of storing rapeseed oil. On this basis, this factor can be considered as not affecting the autoxidation process of vegetable oils, which was also confirmed by [PERSON] [32]. The next parameter to be tested was colorimetric color measurement, for which the CIE Lab method was used. It has been shown that during storage, a decrease in the photometric brightness of the tested samples can be observed (parameter L\({}^{\star}\), meaning oil clarity). The factor influencing the decrease in oil clarity during storage is mainly the packaging in which the oil is stored. In a study conducted by [PERSON] et al., the color changes in stored rapeseed oil samples from different producers were examined and described. In the case of oil samples stored with free access to sunlight, it was found that the value of the L\({}^{\star}\) (photometric brightness) parameter increased over time. This phenomenon can be explained by the higher rate constant of the decomposition of chlorophyll dyes than in the case of carotenoid dyes [33]. This research also observed that the decrease in oil photometric brightness may correlate with air in the packaging. Oils stored in a nitrogen atmosphere showed a less significant decrease in the L\({}^{\star}\) parameter. Moreover, increases in the parameters a\({}^{\star}\) (redness) and b\({}^{\star}\) (yellowness) were observed. According to [PERSON] [16], this may be