## 4 Results and Discussion
### The Cornflower Tincture (Centaurea cyanus L.)  
Cornflowers, _Centaurea L._, are very popular plants belonging to the _Asteraceae_ family. The most popular representative of this family is the blue cornflower _C. cyanus_ L. Cornflower, also called bluecup, despite being a weed is a very important medicinal and cosmetic raw material with anti-inflammatory properties. Dried cornflower petals are components of herbal teas (2019). Blue _C. cyanus_ L. flowers are of great interest as a potential source of natural colouring agents, as well as in food preparation and for decorating dishes (2019). The growing interest in edible flowers has caused cornflower _C. cyanus_ L. to be used to make tinctures. Of all the homemade tinctures that are the subject of this study, the cornflower tincture of _C. cyanus_ L. contains the lowest number of compounds that react with the Folin-Ciocalteu reagent (Table 2). The content of these compounds remains in the tincture of cornflower petals at the level of 9.93 \(\pm\) 0.45 mg GAE/100 mL (Table 2). There is no research conducted so far on the content of polyphenic compounds in tinctures of cornflower petals _C. cyanus_ L. In the studies of [PERSON] et al. (2019) it was demonstrated that the total polyphenol content in cornflower petals was from 393 \(\pm\) 1 to 485 \(\pm\) 8 mg GAE/100 g. In the aqueous extracts of cornflower, [PERSON] et al. (2019) determined 43.48 \(\pm\) 1.33 C mg GAE/g total polyphenols. The homemade tincture of cornflower petals also has a relatively low ability to scavenge DPPH radicals at the level of 9.49 \(\pm\) 2.20% compared to other tinctures tested in this study (Table 2). In the aforementioned studies, [PERSON] et al. (2019) found that the antioxidant activity of extracts by the DPPH radical method ranged from 51 \(\pm\) 1-63 \(\pm\) 1% inhibition. The colour of tinctures from cornflower petals measured with the L* parameter, which means brightness, is very similar for all tinctures and is 23.73 \(\pm\) 0.01 (Table 2). The parameter a* has a negative value of \(-\)0.26 \(\pm\) 0.09, which indicates the absence of red. However, the value of the b* parameter is 3.34 \(\pm\) 0.02, indicating a moderate proportion of yellow (Table 2). In turn, [PERSON] et al. (2019), determined the colour of dried cornflower petals in the CIE L*b* system and obtained the results of 32.5, 4.1, and \(-\)7.9, respectively. Additionally,the study by [PERSON] et al. [34] shows that the colour of cornflower flowers is mainly shaped by anthocyanins, including four cyanidin derivatives. Cluster analysis, carried out on the basis of antioxidant properties and colour parameters of the studied tinctures, allowed us to isolate groups of tinctures with similar profiles (Figure 2). As a result of this analysis, it was found that the tincture's classification to a given cluster is a differentiating factor. The obtained clusters denote tinctures that significantly differ in the values of the determined parameters. With the number of clusters selected for interpretation, the relative homogeneity of the clusters was observed, as well as the fact that they form at a similar binding distance. The larger differences in Euclidean distances allow the assumption that the clusters reflect differing groups of variables. As the quality evaluation for each of the defined clusters, the average value of the grades included in its observed variables was adopted. Three main clusters were identified. The first is formed by two homemade tinctures: cornflower flower tincture _Centaurea cyanus_ L. (Cc) and fresh marigold flowers tincture _Calandula off_. L. (Co_3) and one commercial tincture, the craft tincture of elderberry flowers _Sambucus niger_ L. (Sn_2). Tinctures from this group were characterized by the lowest content of polyphenic compounds--9.93, 10.72 and 13.59 mg GAE/100 mL, respectively. The vast majority of them were characterized by the least intense red colour (negative values of the parameter a*), and were the brightest off all tinctures (high values of the parameter L*).