## 3 Results and Discussion
### Phenolic Content  
The cloudy beetroot juice obtained in this study had the lowest phenolic content (less than 50 mg GAE/100 g). Among the tested beetroot powders, the highest content of total phenols was found in the beetroot juice dried at a reduced temperature and concentrated (J90c), and not subjected to pre-concentration (J90) (Table 4). A similar phenolic content was determined in the powder obtained under typical conditions using traditional spray drying (J130). The powders produced with carriers were characterized by a lower phenol content due to the presence of a carrier (Table 5). The content of polyphenols in the spray-dried beetroot juice mixed with waste (MJ130) was higher than in the powders with carriers (JM130, JN130, JMD130 and JK130), but lower than in the case of juice dried without their addition (J130, J90 and J90c). After converting the amount of phenolics per dry matter of pure beet material used in the process, the highest phenolic content was found in the cloudy juice not subjected to further treatment. The results for the powders obtained with carriers and the powder without a carrier but produced from juice mixed with beetroot waste (MJ130) did not differ significantly (188-215 mg GAE/100 g d.m.) and were lower than the content of phenols in the powder dried without carrier (J130, J90 and J90c), statistically insignificant due to applied conditions (247-266 mg GAE/100 g d.m.). An even smaller content of phenolic compounds was found in the research of [PERSON] et al. (2016) [28]. They investigated the total phenolic content in various beetroot products, including beetroot juice and spray-dried powders. They observed a decrease in the phenolic content from around 380 mg (beetroot juice) to around 90 mg of gallic acid/100 g of d.m. in beetroot powders. It is important to underline that the differences noted by the authors could have resulted from different drying parameters used and the assay conditions that contributed to a greater retention of the components, such as the optimal selection of the solvent used for sample extraction.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Juice** & **MJ130** & **J130** & **J90** & **J90c** \\ \hline \multicolumn{5}{c}{Phenolic content} \\ mg GAE/100 g & 48.88 \(\pm\) 2.82 a  & 178.97 \(\pm\) 5.75 b  & 236.79 \(\pm\) 9.03 c  & 249.551 \(\pm\) 6.67 cd  & 257.67 \(\pm\) 9.23 d  \\ \hline \multicolumn{5}{c}{\(\mathrm{mg\,GAE/100\ g\,d.m.}\)} \\ of dried material & 495.40 \(\pm\) 28.62 c  \\ \hline \multicolumn{5}{c}{Betalain content} \\ mg betalain/100 g & 28.59 \(\pm\) 0.30 a  \\ \multicolumn{5}{c}{307.48 \(\pm\) 16.41 b  } \\ mg betalain/100 g & 289.75 \(\pm\) 3.00 a  & 322.87 \(\pm\) 17.23 b  & 367.64 \(\pm\) 14.85 c  & 702.90 \(\pm\) 10.08 e  & 569.42 \(\pm\) 12.24 d  \\ \hline \multicolumn{5}{c}{CUPRAC} \\ mg Trx/100 g in 70\% & 121.99 \(\pm\) 4.53 a  \\ \multicolumn{5}{c}{acetone} \\ mg Trx/100 g in 70\% & 274.53 \(\pm\) 3.34 a  \\ \multicolumn{5}{c}{302.50 \(\pm\) 22.20 b  } \\ \multicolumn{5}{c}{302.50 \(\pm\) 22.20 c  } \\ \multicolumn{5}{c}{302.50 \(\pm\) 22.20 c  } \\ \multicolumn{5}{c}{2263.60 \(\pm\) 182.32 c  } \\ mg Trx/100 g d.m. of \\ \multicolumn{5}{c}{acetone} \\ mg Trx/100 g d.m. of \\ dried material in 70\% & 328.70 \(\pm\) 9.96 b  \\ \multicolumn{5}{c}{301.94 \(\pm\) 5.11 a  } \\ \multicolumn{5}{c}{228.16 \(\pm\) 5.96 a  } \\ \multicolumn{5}{c}{227.02 \(\pm\) 39.56 a  } \\ \multicolumn{5}{c}{301.38 \(\pm\) 10.96 b  } \\ \multicolumn{5}{c}{303.86 \(\pm\) 10.19 b  } \\ \multicolumn{5}{c}{303.86 \(\pm\) 10.19 b  } \\ \multicolumn{5}{c}{303.86 \(\pm\) 10.18 b  } \\ \multicolumn{5}{c}{302.50 \(\pm\) 18.98 d [FOOTNOTE:b]Footnote b: The differences between the mean values with the same letter in the rows are statistically insignificant (\(p\) \(<\) 0.05).