## 3 Results and Discussion
### Antioxidant Capacity of Extracts
#### 3.4.4 Comparison of the Tested Extracts  
Extracts made using the accelerated solvent extraction method, compared to extracts made using the UAE and SSE methods, were characterised by the significantly highest antioxidant capacity, which amounted to an average of 121.7 \(\upmu\)mol of Trolox/1 g of DW (Figure 11). Also, extracts prepared by shaking them with a solvent had significantly higher antioxidant activity (116.8 \(\upmu\)mol of Trolox/1 g of DW) than extracts prepared with ultrasound-assisted extraction (111.5 \(\upmu\)mol of Trolox/1 g of DW). Studies by [PERSON] et al. [35] and [PERSON] et al. [57] also showed that polyphenol extracts obtained with accelerated solvent extraction are characterised by the significantly highest antioxidant activity. The one-way analysis of variance performed for all types of extracts showed that in addition to the extraction method, the type of solvent used and the cultivar of apple leaves from which the extracts were prepared had a significant impact on the antioxidant activity of the extracts. Water-methanol extracts had the significantly highest antioxidant capacity (average 125.9 \(\upmu\)mol of Trolox/1 g of DW), extracts containing 40% ethanol were second in this respect, while water extracts had the significantly lowest antioxidant activity (average 102.9 \(\upmu\)moles of Trolox/1 g of DW). Among the extracts made from various cultivars of apple leaves, those made from the Ligol cultivar had the highest antioxidant activity (average 119.8 \(\upmu\)mol of Trolox/1 g of DW) and had a significantly higher antioxidant capacity than extracts from the Gala and Gloster cultivars. However, extracts from the leaves of the Gloster cultivar had a significantly higher antioxidant capacity (116.9 \(\upmu\)mol of Trolox/1 g of DW) than extracts from the leaves of the Gala cultivar (an average of 113.3 \(\upmu\)mol of Trolox/1 g of DW). Similarly to the content of polyphenols, [PERSON] et al. [41] found that the antioxidant activity of apple leaf extractsis significantly influenced by the type of solvent used, although to a much lesser extent than the concentration of total phenolic compounds. The results for the antioxidant capacity of the extracts ranged from 58.1 to 65.6 \(\upmu\)mol of Trolox/100 mL, and the increase in ethanol concentration resulted in an increase in the antioxidant activity of the apple leaf extract. Compared with the present study (from 86.8 \(\upmu\)mol of Trolox/100 mL in the water extract obtained with the UAE method, to 121.3 \(\upmu\)mol of Trolox/100 mL in the water-methanol extract) antioxidant activity assumed higher values, which usually increased with increasing alcohol concentration in the extractant. However, when comparing both studies, differences in extract concentration and extraction parameters should be taken into account. [PERSON] et al. [46], [PERSON] and [PERSON] [8], and [PERSON] et al. [6] confirm in their studies that the cultivar of apple leaves has a significant impact on the antioxidant activity of extracts. After conducting a three-factor analysis of variance, eight homogeneous groups were distinguished. Water and methanol extracts from apple leaves of the Ligol and Gala cultivars, obtained using the classical method, had the significantly highest antioxidant capacity (131.2 and 130.4 \(\upmu\)mol of Trolox/1 g of DW, respectively). However, the same homogeneous group included all other water-alcoholic extracts (except the water-ethanol extract from the leaves of the Gala cultivar obtained using the SSE method) and water extracts from apple leaves of the Gala and Gloster cultivars obtained using ASE method. Water extracts from apple leaves of the Gala and Gloster cultivars obtained using UAE method had the significantly lowest antioxidant activity (74.6 and 85.7 \(\upmu\)mol of Trolox/1 g of DW, respectively). Additionally, the latter did not differ statistically from the water extract from Gala leaves obtained using the SSE method.