## 3 Results and Discussion
### Bioactive Compounds in Raspberries Leaves
Studies by other authors on plants of the _Rubus_ family confirm that the content of phenolic compounds and thus their antioxidant activity in different parts of plants and their cultivars can vary due to the genotype of the plant and various cultivation factors, including environmental conditions [56]. In a study conducted on leaves of wild raspberry in the Balkans, a total polyphenol content of 59.68 to 96.83 mg per gallic acid in 1 g of fresh leaf weight was obtained [57]. [PERSON], et al. [40] examined the leaves of many raspberry varieties, including _Polana_, at various stages of growth: during flowering, fruit development and fruit ripening. The total polyphenol content of the _Polana_ cultivar as calculated on GAE was 5890 mg 100 g\({}^{-1}\) DW. With the development of the fruit, the content of polyphenols in the leaves increased, from 6360 mg (flowering), to 3210 mg (fruit development) to the previously mentioned 5890 mg 100\({}^{-1}\) g of DW for fruit ripening. [PERSON] and [PERSON] [58], in their research, focused on determining the differences between conventional and organic cultivations of raspberry leaves. Conventional cultivation raspberries had a statistically lower total polyphenol content, which was not consistent with our results. The high content of total polyphenols in wild and organic raspberry leaves may be due to the fact that plants produce phenolic compounds to protect themselves against increased abiotic or biotic stresses, among other things. This is the plant's natural defense response against the harmful effects of stress factors, such as frost, drought, or intense light radiation, among others. In addition, these compounds protect plants from bacteria, viruses and fungi. Consequently, the plant can increase the production of polyphenols to protect against these organisms [58]. Most studies deal with the content of polyphenols in the raspberry fruit proper and their positive effects on the human body. However, comparing the content of total polyphenols in fruits and leaves of raspberries, it can be concluded that the latter have a significantly higher content of phenolic compounds and can be successfully used in phytotherapy. Other studies also confirmed that the leaves are characterized by greater antioxidant activity than the fruits of the _Rubus idaeus_ raspberry [59]. According to [58], leaves from organic farming had a higher content of antioxidant compounds determined by the ABTS\({}^{\star}\)+ radical than those grown conventionally. [PERSON] [42] in their work found that the determination of antioxidant activity using the ABTS method is significantly influenced by the amount of polyphenols, including flavonoids and ascorbic acid, while other polyphenolic compounds, e.g., anthocyanins contained in raspberry fruit, have a smaller effect. This is confirmed by our research, where the highest total polyphenol content was found in wild raspberry leaves, which also translated into the highest content of antioxidants (determined by the ABTS method). Other studies also showed that different harvest years have an influence on the content of compounds with antioxidant activity [59]. Studies have shown that the content of carotenoids in raspberry leaves from conventional cultivation is higher than in those from organic cultivation [58]. The results obtained in this study confirm this assumption. The high level of carotenoids in the leaves of conventional raspberries was due to the fact that conventional agriculture uses mineral fertilizers containing nitrogen, which in turn increases the production of compounds rich in this chemical element, such as, among other things, chlorophyll. In turn, the level of carotenoids in leaves depends primarily on their chlorophyll content. The higher the content of the green pigment in the leaves, the higher the carotenoid content is found in the plant. This is due to the fact that carotenoids have a protective function over the photosynthetic system against photo-oxidation during photosynthesis [58].