## 3 Results and Discussion
\begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Temp (\({}^{\circ}\)C)**} & \multirow{2}{*}{**Time (min)**} & \multicolumn{4}{c}{**Solvents**} \\ \cline{3-6}  & & **50\% Methanol** & **50\% Ethanol** & **50\% Acetone** \\ \cline{3-6}  & & & **AA (mg/g Rose Fruit Pomace)** & \\ \hline
25 \({}^{\circ}\)C & 15 & 18.53\(\pm\) 0.66 \({}^{\text{Ba}}\) & 21.43 \(\pm\) 1.01 \({}^{\text{Bb}}\) & 25.19 \(\pm\) 0.85 \({}^{\text{Ac}}\) \\
25 \({}^{\circ}\)C & 30 & 19.83 \(\pm\) 0.36 \({}^{\text{Ba}}\) & 23.00 \(\pm\) 0.90 \({}^{\text{Bb}}\) & 26.87 \(\pm\) 0.03 \({}^{\text{Bc}}\) \\
25 \({}^{\circ}\)C & 45 & 21.45 \  
vitamin C decreases in the following order: water, methanol, ethanol, acetone, acetonitrile, and ethyl acetate. The content of AA in the extracts (25 \({}^{\circ}\)C, after 60 min) ranges from 3.47 mg AA/g of freeze-dried rose fruits pomace for acetone extract to 34.42 mg AA/g of freeze-dried rose fruits pomace for water (Table 4). The content of AA in the extracts (45 \({}^{\circ}\)C, after 60 min) ranges from 3.64 mg AA/g of freeze-dried rose fruits pomace for acetone extract to 35.18 mg AA/g of freeze-dried rose fruits pomace for water (Table 4). The content of AA in the extracts (65 \({}^{\circ}\)C after 60 min) ranges from 3.29 mg AA/g of freeze-dried rose fruit pomace for acetone extract to 31.33 mg AA/g of freeze-dried rose fruit pomace for water (Table 4). The use of 50% acetone or 50% ethanol (Table 5) as a solvent showed higher recoveries of L-ascorbic acid in rose fruits pomace compared to acetone and ethanol (Table 4). These recoveries were higher on average for the three temperatures (25 \({}^{\circ}\)C, 45 \({}^{\circ}\)C, and 65 \({}^{\circ}\)C) by approximately 87% and 48% for 50% acetone and 50% ethanol, respectively. The higher extraction efficiencies obtained during extraction using 50% acetone and 50% ethanol can be attributed to the presence of water, which can increase the polarity of the solvents. These results can be compared with the research conducted by [PERSON] et al. [56], who reported an average vitamin C content of 3500 mg/100 g dry weight (DW). [PERSON] et al. [45] showed that the optimal condition for the ultrasound-assisted extraction (UAE) of AA from rose fruits (_Rosa rugosa_) was 50% ethanol for 30 min. at 30 \({}^{\circ}\)C. The content of AA in the extract (30 \({}^{\circ}\)C, after 30 min) was 6.38 mg AA/g dry weight (DW). Differences in the content of L-ascorbic acid depend on many factors, such as species, degree of maturity, and type of climate. [PERSON] et al. [57] conducted research comparing different species of roses in terms of the content of L-ascorbic acid. The results ranged from 510 to 2250 mg/100 g dry weight (DW). _Rosa villosa_ had the highest content, while _Rosa canina_ L. had the lowest content. Other researchers reported significant differences in the vitamin C content of _Rosa corymbifera_ (760.52 mg/100 g), _Rosa rugosa_ Thunb. (577.13 mg/100 g), _Rosa alba_ L. (733.86 mg/100 g), and _Rosa canina_ L. (628.11 mg/100 g) cultivated in the same growing conditions [58]. [PERSON] et al. [59] showed significant differences in the content of vitamin C in fresh (429.55 mg/100 g dry matter) and dried (187.67 mg/100 g dry matter) rose hips (_Rosa canina_). The vitamin C content in dried rose hips was significantly reduced by 56.3% compared to the initial value in the fresh sample. As the extraction temperature was lowered (25 \({}^{\circ}\)C), the concentration of L-ascorbic acid remained at a similar level in the tested pomace over time. At higher temperatures (45 \({}^{\circ}\)C and 65 \({}^{\circ}\)C), a higher content of L-ascorbic acid was demonstrated, but also faster degradation after 30 min of extraction. The decrease in vitamin C content after exceeding a certain temperature may be due to the fact that it is a thermolabile vitamin. Testing the vitamin C content in pomergnate juice at different temperatures showed a constant concentration of vitamin C at 90 \({}^{\circ}\)C for a period of 15 to 75 min [60].