## 4 Discussion  
In our study, the effect of long-term storage of homemade nalewkas containing seasonal fruits, such as cherries, plums, strawberries, currants, raspberries, and quince, on their antioxidant activity was evaluated. The antioxidant activity of the analyzed nalewkas was measured using the DPPH, ABTS, FRAP, and CUPRAC methods. The total polyphenol (TPC), anthocyanin (TAC), total tannin (TTC), and gallic acid content were also analyzed. Figure 10: The content of gallic acid in three types of nalewkas in 1997 and 2013–2019. Values are the mean of three determinations (n = 3). Different letters indicate significant differences between all types of nalewka in individual years (\(\alpha\) = 0.05). Figure 9: An example of a chromatogram for the determination of gallic acid. A sample of plum nalewka from 2019, the sample was diluted 100 times. The retention time of gallic acid was 2.650 min. Nalewka is a traditional Polish alcoholic beverage made by maceration, among others, of fruit with or without the addition of sugar in pure ethanol or vodka. To obtain such beverages, popular and widely cultivated fruits rich in valuable ingredients with antioxidant properties are often used. All of our tested nalewkas showed antioxidant activity, but it depended on the year of production as well as the type of fruits used. Many authors have reported the antioxidant capacity of various natural alcoholic beverages containing, among others, fruits [9; 15; 47], nuts [16; 17], or tea leaves [48]. The antioxidant properties of traditional Polish nalewkas were also assessed by [PERSON] and [PERSON]. They proved the highest antioxidant activity, measured with the DPPH method for the elderberry nalewka (1045 umol/100 mL), then for the raspberry nalewka (285 umol/100 mL) and the cherry nalewka (133 umol/100 mL), whereas the lowest for the cranberry nalewka (45 umol/100 mL) [13]. Many studies report that the antioxidant activity depends on the time of storage [9; 17]. This was also confirmed in our analyses, in which a significant decrease in antioxidant activity with increased storage time was observed. The youngest nalewkas, produced in 2017-2019, have been most often characterized by significantly the highest antioxidant activity. However, according to many authors, the antioxidant activity of fruit and herbal liqueurs after prolonged storage does not always decrease. Many factors can affect this parameter, such as the type of fruit or herb used, storage conditions, and the scheme of the preparation of alcoholic beverages. For example, [PERSON] et al. evaluated the antioxidant activity of 17 homemade nocino liqueurs, each made in a different year (from 1977 to 2000). The authors did not show a significant difference between the antioxidant activity in the younger liqueurs compared to the older ones. DPPH radical scavenging activities of the older samples produced in 1977-1983 were similar to younger samples produced in 1996-2000, wherein the average activity expressed as Trolox equivalents for all samples was 199 umol Trolox/100 mL [17]. [PERSON] et al. suggested that storage time can influence on activities of samples evaluated with the DPPH method and may cause either increasing or decrease of antioxidant activity. The authors compared the antioxidant capacity of liqueurs made from red fruits, such as chokeberry (_Aronia melanocarpa_ (Michx.) [PERSON]), cornelian cherry (_Prunus avium_ L.), black rose (_Rosa spinoississima_ L.), blackcurrant (_Ribes nigrum_ L.), blackberry (_Vacinium myrtillus_ L.), raspberry (_Rubus ideatus_ L.), rhamonia (_Malonia aquifolium_ ([PERSON]), sole (_Prunus gynice_ L.), strawberry (_Fragaria \(\times\) anatasa_) and sour cherry (_Cerasus vulgaris_ Mill.). All liqueurs were prepared using 65% (\(\
icefrac{{n}}{{v}}\)) ethanol. The authors analyzed, among others, the influence of 6 months of storage at 15 \({}^{\circ}\)C and 30 \({}^{\circ}\)C on the antioxidant potential of the samples. During storage, it was observed a different decrease in antioxidant activity depending on the type of liqueurs.