## 3 Results and Discussion
### Antioxidant Activity
In contrast to the reducing capacity, compounds isolated with 70% acetone (47 mg Trolox/100 g) had a greater activity using the hydrogen atom transfer deactivation mechanism than those with buffer (26 mg Trolox/100 g) in the juice, used for drying. However, in powders, similarly to the CUPRAC method, a greater activity was recorded in the case of compounds isolated with buffer, which were almost twice as effective each time (Tables 4 and 5). The highest activity was achieved by powders dried at a lower temperature: concentrated before drying (J90c; 546 mg Trolox/100 g) and unconcentrated (J90; 457 mg Trolox/100 g). The lowest activity was again found in the extracts from products dried with carriers (120-139 mg Trolox/100 g in 70% acetone and 231-288 mg Trolox/100 g in buffer). The product dried with added waste (MJ130) had a similar activity and the juice dried without any carrier at the standard temperature (J130) had an intermediate activity. After converting the activity into 100 g d.m. of the material from beetroot, it was found that the high activity of compounds extracted with 70% acetone from juice (475 mg Trolox/100 g d.m.) was reduced to approximately 300 mg (powders obtained at a lower temperature: J90 and J90c) and 161-188 mg Trolox/100 g d.m. (powders obtained with carriers; Table 5). In the case of the extracts in buffer, the trend was maintained at higher values: juice activity (265 mg Trolox/100 g d.m.) slightly increased after obtaining products with and without carriers at higher temperature (286-343 mg Trolox/100 g d.m.) and up to 474-564 mg Trolox/100 g d.m. in products obtained under reduced drying temperatures. These trends (with slightly changed proportions of the obtained values) are therefore consistent with the observations regarding the reducing capacity. The antiradical activity against DPPH\({}^{\bullet}\) could only be determined in the extracts in 70% acetone (due to the presence of opalization-forming phosphate buffer salts in the remaining extracts) and could be compared to the activity of analogous extracts against ABTS\({}^{+}\). First of all, the activity of the extracts against DPPH\({}^{\bullet}\) radicals was clearly lower than that detected with respect to ABTS radical cations (Tables 4 and 5). These methods accept both mechanisms; however, one is often preferred. Antioxidants against ABTS\(\bullet\)+ under these conditions are more effective using the SET mechanism (buffered environment with increased pH), and against DPPH\(\bullet\)ather the HAT mechanism (aprotic solvent containing water), which was confirmed in this study [30]. The activity against DPPH\({}^{\bullet}\) radicals was similar in all of the produced powders (118-126 mg Trolox/100 g d.m. with carriers: JM130, JN130, JMD130 and JK130; 192 mg Trolox/100 g d.m. from juice with added beetroot waste: MJ130; 219 mg Trolox/100 g d.m. dried without carrier and without preliminary concentration: J90; and the highest value of 300 mg Trolox/100 g d.m. dried at a low temperature after preliminary concentration: J90c). In the case of ABTS**, the powders with carriers had very similar activity: 348-365 mg Trolox/100 g d.m. (Table 5), and the powder obtained from juice with a carrier had an activity much closer to the high activity obtained without carriers (618-662 mg Trolox/100 g d.m.). After taking into account only the activity originating from the beetroot material, even more balanced values were found (462-684 mg Trolox/100 g d.m. ), although clearly lower than the activity of compounds in the juice before drying (1576 mg Trolox/100 g d.m. ), which is characteristic of the HAT mechanism. However, the antiradical activity of the cloudy juice extract in the buffer against ABTS** was over ten times higher (1756 vs. 155 mg/100 g), which indicated the involvement of the SET mechanism, and in the obtained powders it was equal and close to that detected in the juice (1380-2806 mg/100 g). However, such a phenomenon did not occur in the previously discussed methods.