## 3 Results and Discussion
### Effect of the Pre-Treatment on the Properties of Dried Material
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Type of** & **L\({}^{\star}\) (\(\circ\))** & **a\({}^{\star}\) (\(\circ\))** & **b\({}^{\star}\) (\(\circ\))** & **h (\({}^{\circ}\))** & **\(\Delta\)E (\(\circ\))** \\ \hline untreated & 51.5 \(\pm\) 4.4 ab & 17.6 \(\pm\) 2.9 a & 32.5 \(\pm\) 2.3 a & 61.7 \(\pm\) 3.9 a & 15.8 \(\pm\) 2.9 ab \\
5 s EtOH & 45.3 \(\pm\) 3.3 c & 21.3 \(\pm\) 4.2 a & 27.2 \(\pm\) 3.1 b & 52.3 \(\pm\) 4.2 b & 11.7 \(\pm\) 4.1 bc \\
15 s EtOH & 48.4 \(\pm\) 3.5 bc & 18.5 \(\pm\) 2.8 a & 26.3 \(\pm\) 2.8 b & 54.9 \(\pm\) 3.5 b & 11.3 \(\pm\) 2.5 bc \\
60 s EtOH & 45.0 \(\pm\) 3.8 c & 19.3 \(\pm\) 3.0 a & 25.7 \(\pm\) 2.7 b & 53.2 \(\pm\) 2.4 b & 9.7 \(\pm\) 2.9 c \\
180 s EtOH & 49.8 \(\pm\) 4.8 abc & 18.9 \(\pm\) 4.6 a & 27.9 \(\pm\) 3.5 b & 56.2 \(\pm\) 3.9 ab & 13.8 \(\pm\) 3.5 abc \\
5 s EtOH+US21 & 51.6 \(\pm\) 4.9 ab & 21.0 \(\pm\) 2.2 a & 28.7 \(\pm\) 3.4 ab & 53.8 \(\pm\) 2.0 b & 15.6 \(\pm\) 4.4 ab \\
15 s EtOH+US21 & 52.9 \(\pm\) 4.6 ab & 21.1 \(\pm\) 3.1 a & 26.9 \(\pm\) 2.5 b & 52.1 \(\pm\) 3.8 b & 16.1 \(\pm\) 3.9 ab \\
60 s EtOH+US21 & 55.2 \(\pm\) 4.7 a & 20.4 \(\pm\) 3.3 a & 26.6 \(\pm\) 1.6 b & 52.6 \(\pm\) 4.5 b & 17.4 \(\pm\) 4.5 a \\
180 s EtOH+US21 & 54.0 \(\pm\) 4.2 b & 22.3 \(\pm\) 3.7 a & 28.3 \(\pm\) 3.3 b & 51.9 \(\pm\) 3.4 b & 18.1 \(\pm\) 3.8 a \\ \hline \hline \end{tabular}  
* a, b, etc.—different letters indicate different homogeneous groups (one-way ANOVA, \(\alpha\) = 0.05). The results of two-way ANOVA indicate the significance (\(\uparrow\)) or insignificance (\(\downarrow\)) of the influence of the type and time of treatment (\(\alpha\) = 0.05).  
\end{table} 
Table 5: Colour parameters (L\({}^{\star}\), a\({}^{\star}\), b\({}^{\star}\)), hue angle (h\({}^{\circ}\)) and total colour difference (\(\Delta\)E, in comparison to raw material) of carrot tissue pre-treated in ethanol without (EtOH) and with ultrasound (EtOH+US21); error bars indicate \(\pm\) SD (standard deviation calculated from at least six repetitions). As in the case of the material directly after processing in ethanol (Figure 2), as well as in the case of dried carrots, increased content of carotenoids after treatment in ethanol was observed (up to 135% increase in comparison to untreated dried carrot). This was linked to the use of immersion in ethanol, and higher carotenoid content was obtained with longer processing time (\(p\) < 0.05, Figure 5) and with sonication assistance. However, the second factor did not affect significantly the obtained results (\(p\) > 0.05, Figure 5). The increased carotenoid contents in relation to untreated dried material was in the range of 37-115% and 43-135% in the case of EtOH and EtOH+US, respectively. Ultrasound caused thus only a slight increase in carotenoid content in dried carrots in relation to the dried material immersed in ethanol. These results are confirmed by the reports of [PERSON] et al. (2018) and [PERSON] (2018). However, pumpkin subjected to 30 min of ethanol with US and convective drying at 50 \({}^{\circ}\)C retained 100% of carotenoids, while control samples showed 23% degradation of carotenoid content ([PERSON] et al., 2018). Furthermore, [PERSON] (2018) observed unchanged carotenoid contents in dried carrots treated with ethanol for 30 min compared to the untreated dried material. It should be, however, mentioned that in our study the increased content of carotenoids after a shorter amount of time indicates the possibility of obtaining product of designed properties when the pre-treatment parameters are adjusted. Furthermore, it is worth mentioning that due to enhanced extractivity of carotenoids, the immersion in ethyl alcohol with US assistance for 180 s resulted in limited degradation of carotenoids (8%) in dried material when compared to fresh tissue. It can be therefore stated that dried carrot subjected to EtOH+US treatment contained a similar amount of carotenoids as raw root.