## 3 Results and Discussion  
The hemp seeds selected for research differed in their physical parameters. Particularly, significant differences could be seen in the seeds' oil content and size. The Earlina 8 FC variety was characterized by the highest seed oil content (>31%), the smallest size (1.096 mm), and therefore the highest bulk density (521.00 kg/m\({}^{3}\)). Moreover, this variety achieved the best efficiency in terms of the pressing process both at low temperatures (>69%) and at high temperatures (>79%). [PERSON] et al. [32] previously indicated that the oil yield increases with an increase in the processing temperature, which was confirmed by the results obtained in this study. Moreover, pressing the Secuieni Jubileu variety, which has the largest seeds, showed the lowest efficiency when pressed at low temperatures. In the case of pressing at elevated temperatures, it was similar to the Finola variety. Based on this, it can be concluded that the effectiveness of the low-temperature stamping process also depends on the size of the raw material, which was also noticed by [PERSON] et al. [33] The parameters of the seeds used and the pressing efficiency are presented in Table 1.  
Two studies ([PERSON] et al. and [PERSON] et al. [34; 35]) have previously indicated that an increase in pressing temperature is associated with a deterioration in the organoleptic properties of the oils obtained (decrease in clarity, darker color) and a change in the content of natural dyes. The amount of chlorophylls increases, but the amount of valuable components (carotenoids, sterols) decreases, and unsaturated fatty acids are degraded. Our preliminary analysis confirmed these results. The oils obtained from low-temperature pressing were characterized by a lighter color and greater clarity than those obtained at elevated temperatures, as indicated by the results of tests using the CIE Lab method. Increasing the pressing temperature causes an increase in the L* parameter (photometric brightness), a* parameter (greenness for negative or redness for positive values), and b* parameter (blueness for negative or yellowish for positive, values) of the tested oils (i.e., ultimately, a darkening of the oils). Pressing at high temperatures causes a significant increase in the content of chlorophyll pigments (23-31%, depending on the variety). The Earlina 8 FC variety was characterized by the smallest growth in chlorophyll content and \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & & \multicolumn{3}{c}{**Hemp Variety**} \\ \cline{3-5}  & & **Finola** & **Earlina 8 FC** & **Secuieni Jubileu** \\ \hline \multirow{4}{*}{Parameter} & Oil content [\%] & 29.97 & 31.04 & 29.47 \\  & Seed size [mm] & 1.152 & 1.096 & 1.213 \\  & Average moisture content [\%] & 8.389 & 8.319 & 8.312 \\  & Average bulk density [kg/m\({}^{3}\)] & 516.06 & 521.00 & 506.73 \\  & CP efficiency [\%] & 66.26 & 69.26 & 62.66 \\  & HP efficiency [\%] & 75.19 & 79.40 & 76.12 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Selected parameters of the hemp seeds used in this study and their pressing efficiency. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & & \multicolumn{3}{c}{**Parameters**} \\ \cline{2-5}
**Oil** & **L*** & **a*** & **b*** & **Chlorophylls** & **Carotenoids** \\  & **L*** & **a*** & **b*** & **[\(\mu\)g/mL]** & **[\(\mu\)g/mL]** \\ \hline Finola CP & 42.13 & 1.51 & 24.66 & 90.1 & 11.5 \\ Finola HP & 50.42 & 5.17 & 40.38 & 117.9 & 8.7 \\ Earlina 8 FC CP & 37.89 & 0.99 & 20.14 & 81.2 & 17.3 \\ Earlina 8 FC HP & 47.91 & 3.92 & 36.67 & 102.1 & 14.8 \\ Secuieni Jubileu CP & 45.01 & 2.12 & 26.81 & 106.7 & 12.9 \\ Secuieni Jubileu HP & 54.03 & 6.84 & 43.11 & 131.4 & 10.6 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results of the preliminary analyses of the different varieties of hemp oils. the highest increase was observed in Finola variety. In the case of the range of carotenoid pigments, their decrease was observed from 13% for the Earlina 8 FC variety to 32% for the Finola variety.