## 4 Discussion
If the beverage production process involves heat treatment, the caramelization products of sugar compounds also influence the ultimate product's color [17]. A previous study has shown that the extraction of red rose petals with 50% ethanol in a first variant and with a sucrose solution in a second resulted in the release of colored compounds into both solutions. However, the alcohol solution showed a clearly more intense color [22]. Another study demonstrated that liqueurs made of fresh hawthorn fruits subjected to a sweetening process with a 65% sucrose solution at 65 \({}^{\circ}\)C for 35 min before extraction showed higher values of all color parameters (L\", a\", b\", C\", h\({}^{\circ}\)) than liqueurs produced from unsweetened fruits. In addition, it showed that changes in the a\" parameter correlated positively with the content of anthocyanins in the samples [14]. The liqueurs analyzed in the present study were characterized by a dark purple, intense color, which may be attractive to potential consumers. The measurements showed statistically significant differences between the values of all of the determined color parameters (L\", a\", b\", C\", h\({}^{\circ}\)). However, the total color difference calculated on their basis was so small that it could not be perceived by an ordinary observer; however, it was perceptible to the trained panelists conducting the organoleptic assessment. The lowest color score was given by the panelists to the berry liqueur, whose measured color intensity (chroma) was the highest. It additionally showed the highest contribution of red color in the color profile (Figure 1, Table 2). However, it is noteworthy that the measured chroma was weakly correlated with the overall organoleptic quality of the tested beverages (correlation coefficient value of \(-\)0.27). In the case of wild passion fruit liqueur, similarly to the berry liqueurs, the panelists preferred beverages with a higher proportion of blue, but with a more saturated, dark color. In this case, all color parameters were strongly correlated with consumer preferences [17]. The analysis of consumer preferences for _A. humile_ liqueurs revealed greater acceptability of the light-colored products [18]. According to [PERSON] et al. (2015) [23], the color of a food product is a feature of great importance to consumer expectations. A change in either the intensity or saturation of the color of beverages can positively or negatively affect their final acceptability. The phenolic compounds found in fruit alcoholic beverages contribute to their astringent but pleasant flavor and aroma [24]. They can also mitigate the harmful (pro-oxidative) effects of alcohol [8], provided that it is consumed in moderate amounts. Therefore, as high as possible a content of phenolic compounds is desirable in liqueurs. In the present study, the highest content of phenolic compounds was determined in the berry liqueur sweetened with cane sugar (109.16 mg gallic acid/100 mL), whereas in those sweetened with xylitol and stevia, it reached 95.36 and 92.93 mg gallic acid/100 mL, respectively. It is noteworthy that the decrease was no greater than 17.5%. This may have been caused by the interaction of xylitol and stevia with polyphenic compounds, or by the positive effect of sucrose on the process of extraction of these compounds from fruit. In the case of the _A. humile_ liqueur, the total content of phenolic compounds depended on the maturation time, i.e., the longer the maturation time, the higher the content of phenolic compounds in the liqueur. The content of phenolic compounds in the liqueur macerated for 17 days was 10.59 mg gallic acid/100 mL. It was also found that the maturation time had a greater effect on the content of phenolic compounds in the final product compared to the amount of fruit pulp used [18]. On the other hand, the maceration time clearly affected the content of polyphenic compounds in the liqueur produced from grape stems.