# From Forest Berry Leaf Waste to Micellar Extracts with Cosmetic Applications
## 3 Results and Discussion  
### Active Ingredient Contents in Berry Plant Leaves  
#### 3.1.1 Content of Micro- and Macronutrients in Plant Leaves  
Minerals play a vital role in maintaining the proper functioning of the human body, including promoting healthy skin and hair. Zinc, for instance, is an essential mineral involved in processes such as wound healing, similar to iron, and the prevention and treatment of acne [39; 40]. Another mineral, copper, among its other functions, acts as a protective agent against free radicals, stimulates skin fibroblast proliferation, and serves as a cofactor for tyrosinase, an enzyme crucial for melanin biosynthesis, which plays a significant role in skin and hair pigmentation [41]. Considering the above aspects, the micro- and macronutrients present in the leaves of berry plants were analyzed, and the results are presented in Table 3a,b. Among all the elements studied (Table 3a,b), calcium was found to be the most abundant in the examined plant leaves, with concentrations ranging from 767.49 mg/100 g in the blueberry leaves to 2083.99 mg/100 g in the wild strawberry leaves. The leaves of the wild strawberries exhibited the highest concentrations of other macronutrients, including potassium (1372.67 mg/100 g), magnesium (352.00 mg/100 g), and phosphorus (187.32 mg/100 g). In comparison, the blueberry leaves contained significantly lower levels of these elements, with amounts 3 to 4 times lower than those found in the wild strawberry leaves (Table 3b). High levels of macronutrients in the various vegetative parts of wild strawberry plants were highlighted by [PERSON] et al. [42], who emphasized that the leaves and stems are far superior sources of these compounds compared to the roots. Their research also indicated that wild-grown Fragaria vesca shrubs were a better source of calcium and magnesium compared to those cultivated commercially. The effects of the crop type, variety, and harvest time on the mineral content in the wild strawberries were also reported by [PERSON] and [PERSON] [43] and [PERSON] et al. [15]. An analysis of the micronutrient levels revealed that the wild strawberry leaves were particularly rich in iron, containing 111.91 mg/100 g of this element, which is over 10 times the amount determined in blackberry leaves (9.64 mg/100 g) and more than 25 times that in blueberry leaves (4.19 mg/100 g) (Table 3a). The high iron content in the leaves and stems of wild strawberries was also reported by [PERSON] et al. [42], who measured it at 45.3 mg/100 g. Their findings indicate that, depending on the varietal and genetic characteristics of the plants, the differences in iron content can vary up to 12-fold. The impact of these factors on the mineral composition of shrub leaves was also examined by [PERSON] and [PERSON] [44], who analyzed blackberry leaves and found that their iron content was similar to that shown in Table 3a (6.16 mg/100 g). A slightly higher level of this element, ranging from 7.06 to 7.66 mg/100 g, was determined by [PERSON] et al. [45] in blackberry leaves cultivated using various methods, while [PERSON] et al. [46] reported that blackberry leaf buds, depending on cultivation methods, contained iron in the range from 11.77 to 19.14 mg per 100 g.  
The wild strawberry leaves analyzed in this study were also identified as the best source of copper (0.73 mg/100 g). However, the differences in the copper content were not as significant as for the previously mentioned elements, with the blackberry and blueberry