## 1 Introduction
Thanks to the scientific evidence proven and presented so far, we can confidently classify such plant extracts as natural food preservatives [18]. One of the simplest methods of obtaining bioactive ingredients is the extraction of plant material with a solvent. Post-production waste from plant materials from various industries is also perfect for this purpose. Most often, pomace is used, which may also contain large amounts of valuable bioactive ingredients. The extraction process involves the separation of a specific ingredient from the mixture using a solvent by diffusion. The effectiveness of this process depends primarily on the type of solvent but also on the temperature, extraction time, solid-to-solvent ratio, number of extractions, and partial size of the sample material [24; 25]. The most important criterion for effective extraction is the appropriate adjustment of the solvent. The most commonly used solvents for extracting active substances from plant material are water, ethanol, methanol, acetonitrile, acetone, hexane, and chloroform. The appropriate selection of the extractant should be based on knowledge of the chemical nature of the extracted substance and the solvent. The temperature used is also a very important element in the extraction process because increased temperature affects the loss of labile compounds. Polar solvents are most often used to extract polyphenic compounds and vitamin C from plant material [26; 27; 28]. The recovery of phenolic compounds during extraction is closely related to their chemical structure. An example of this is gallic acid, which is the most soluble in water because its molecule has four hydroxyl groups and one carboxyl group. The study by [PERSON] et al. [29] showed that water, due to its higher polarity coefficient, washes out more polyphenols from the solid than ethanol. According to [PERSON] [30], increasing the share of ethanol in the solvent mixture results in better extraction due to the reduction of the dielectric constant of the solution, which is directly related to the reduction of the energy needed to separate the solvent molecules. Based on research, it is known that chlorogenic acid and flavonoids are better extracted with ethanol [31; 32]. In comparison, aqueous acetone is best for extracting higher molecular weight flavanols, and methanol is best for extracting lower molecular weight polyphenols [33]. Ethanol has less toxicity compared to acetone, methanol, and other organic solvents [34]. The use of extraction solvents in industry requires consideration of, among others, factors such as solvent residue in the product, its removal, and environmental pollution [35]. The most recommended solvent for extraction is water, due to features such as non-toxicity, ecological nature, low cost of use, high extraction potential, and no restrictions on human consumption [33]. According to the European Pharmacopoeia, only class 3 solvents such as ethanol and acetone can be used in pharmaceutical products because they are less toxic and pose less risk to human health [36]. In contrast, solvents such as acetonitrile, chloroform, hexane, and methanol must be limited in pharmaceutical products due to their inherent toxicity. The concentration limits of these products for acetonitrile, chloroform, hexane, and methanol are 400, 60, 290, and 3000 ppm, respectively [36]. To the best of our knowledge, there is no study investigating the effect of different solvents on the recovery of phenolic compounds and L-ascorbic acid from rose fruits pomace waste. The aim of this study was to investigate the effects of temperature, time extraction, and different solvents, including water, methanol, ethanol, and acetone, and the combination of these organic solvents with water in a ratio of 50:50 (\(v/v\)) on the recovery of total phenolic compounds (measured by Folin-Ciocalteu) and L-ascorbic acid (measured by the HPLC method) of rose fruits (_Rosa rugosa_) pomace.