## 4 Discussion
During 24 weeks of storage, the total phenolic content before storage was 1.15 mg GA/mL, whereas, after storage, it was 1.10-1.14 or 1.21-1.25 mg GA/mL in samples without and with sugar, respectively [11]. In our research, during the last 2 years of storage (2018 and 2019), no significant changes in total polyphenol were observed in all naekwas. However, in the literature, there are not many reports on the analysis of alcoholic beverages with added fruits after 25 years of storage. Only [PERSON] et al. stated that the mean total phenol content of nocino liqueur from 1977-2000 reached 2758 mg/L and did not significantly decrease upon the liqueur aging if they were stored at 15-18 \({}^{\circ}\)C. The nocino liqueur is made with green, unripe walnuts and is a typical nalewka containing a very high content of tannins, which probably also affects the stability of these tinctures [17]. An important parameter in the evaluation of alcoholic fruit beverages is the color for which some secondary metabolites are responsible, among others anthocyanins. All analyzed by us nalewkas were characterized by a characteristic color. The darkest product was cherry nalewkas, which is due to the high content of anthocyanins [11]. Visually, the color of samples from different years of production was similar. Therefore, we decided to estimate the percentage share of individual colors in all nalewkas in individual years of production. The largest percentage share in the primary colors was yellow, while the lowest was blue. [PERSON] et al., who studied the color parameters of Nepali wines, have made similar observations. In the wines they examined, the dominant colors were red and yellow, with a small share of blue. The authors explain this phenomenon by the fact that the proportion of red color is mainly derived from anthocyanins and decreases as anthocyanin polymerizes with tannins and other phenolic compounds, which leads to the increase in yellow color proportion. The intensification of this process was observed with the age of the wine [42]. We observed a similar tendency in our nalewkas. The nalewkas from 2019, in particular ratiafa and cherry, were characterized by the highest concentration of anthocyanins and the highest share of red color, whereas the nalewkas from 1997 were characterized by the lowest concentration of anthocyanins. In the case of plum nalewka, the low concentration of anthocyanins was reflected in the color of the nalewka, in which the highest share of yellow was found. The anthocyanins, as pigments, are almost exclusively responsible for the blue, red, and purple colors in fruits [53]. Anthocyanins are natural dietary pigments that could also be involved in health effects [54]. These compounds are known to be functional compounds of a healthy diet and belong to polyphenolic organic compounds. These natural pigments are essential secondary metabolites characterized by powerful antioxidant activity [55]. In our study, the total anthocyanin content of nalewkas varied depending on the production year as well as the type of nalewka. The older nalewkas contained significantly fewer anthocyanins as compared to the younger ones. An interesting result was observed in the case of cherry nalewka, in which the content of anthocyanins remained at a similar level over the last 7 years. In the case of the other nalewkas, high content of anthocyanins was found only in the last four and three years for ratiafa and plum nalewka, respectively. [PERSON] et al. in their study stated, that anthocyanins underwent a partial or completely significant degradation during 6 months of storage in various of fruit liquefurs [9]. Similarly, [PERSON] et al. (2007) observed a lower content of anthocyanins in the cornelian cherry liqueur after three months of storage, wherein the color of liqueurs turned more into yellow [56]. Anthocyanins are undurable pigments, susceptible to oxidation, especially in case of ascorbic acid presence [11]. In our study, the lowest degradation of anthocyanins during storage in cherry nalewka were observed.