## 3 Results
### Antioxidant Activity  
The antioxidant activity of raw buckwheat honey and spray dried powders, expressed as EC\({}_{50}\) ABTS--a material's ability of scavenging 50% of free radicals in ABTS solution--was 2.69 \(\pm\) 0.00 mg solids\(\cdot\)ml\({}^{-1}\) for raw honey, and for powders it ranged from 0.18 \(\pm\) 0.00 to 8.24 \(\pm\) 0.36 mg solids\(\cdot\)ml\({}^{-1}\) (Table 3) [54]. Obtained results point to the significant effect of carrier type in all variants and drying parameters for variants where MD was used as a carrier. The highest antioxidant activity was noted for variants where MP was applied as a carrier, which further strengthened the authors confidence in MP's validity in buckwheat honey spray drying. [PERSON] et al. (2020) reported the same effect of MP in dehumidified-air-assisted spray drying of honey [17]. The authors noted better results in powders' antioxidant activity in comparison to other carriers (maltodextrin, kleptose, NUTRIOSE(r)). It should be emphasized as well that higher antioxidant activity was observed for powdered honey in the case of MP variants (in contrast to MD variants) than for raw buckwheat honey. [PERSON] et al. (2019) underlined that a concentration of milk present in the honey powder as a carrier should be considered in antioxidant activity as  
\begin{table}
\begin{tabular}{c c c c} \hline
**Variant** & \(L^{\star}\) & \(a^{\star}\) & \(b^{\star}\) \\ \hline SDMD50 & 83.7 \(\pm\) 0.3 c & +0.6 \(\pm\) 0.1 e & 13.7 \(\pm\) 0.3 b \\ DASDMD50 & 86.7 \(\pm\) 0.5 f & 0.0 \(\pm\) 0.0 b & 10.4 \(\pm\) 0.4 a & \\ DASDMD75 & 84.3 \(\pm\) 0.4 d & +0.4 \(\pm\) 0.0 d & 14.3 \(\pm\) 0.2 c & \\ SDMP50 & 79.8 \(\pm\) 0.1 a & +0.6 \(\pm\) 0.1 e & 23.8 \(\pm\) 0.9 f & \\ DASDMP50 & 84.9 \(\pm\) 0.3 e & \(-\)0.5 \(\pm\) 0.1 a & 15.8 \(\pm\) 0.4 d & \\ DASDMP75 & 83.1 \(\pm\) 0.3 b & +0.2 \(\pm\) 0.1 c & 17.3 \(\pm\) 0.3 e & \\ \hline \end{tabular} a–d the differences between mean values with the same letter are statistically insignificant (\(p<\) 0.05).  
\end{table}
Table 5: Color parameters \(L^{\star}a^{\star}b^{\star}\) of buckwheat honey powders obtained by high temperature traditional spray drying (SD) and low temperature spray drying with the application of dehumidified air (DASD) with maltodextrin (MD) and milk powder (MP) as a carrier, containing 50–75% honey solids.  
sessment, as milk itself manifests antioxidant activity due to its composition [55]. However, the presented results do not seem to confirm this observation, as carrier concentration did not affect powders' antioxidant activity with regard to MP variants. It should be outlined as well that the formation of products of Maillard reaction could have affected the antioxidant activity of MP variants in comparison to MD variants. The color analysis (Table 5) indicated that MP variants were more susceptible to browning than MD variants, suggesting greater formation of Maillard reaction products in the powder and consequently ameliorating the antioxidant activity of final product. However, this correlation was not assessed by the Pearson coefficient (Table A1). Nevertheless, the findings of this research likely imply the protective effect of MP on buckwheat honey spray drying. Moreover, there was no statistically significant effect of drying parameters on antioxidant activity with regard to powders spray dried with MP as a carrier. Generally speaking, high drying temperatures deteriorate antioxidant activity [55]. However, in this research this relationship was not observed. As can be noted, MD variants manifested lower antioxidant activity than MP variants, and variants spray dried at lower drying temperature and with high carrier content (DASDMD50) can be considered as the worst variants to scavenge free radicals. However, obtained results would seem to suggest that smaller particles in variant DASMD50 consequently increased the particle surface exposed to the heat, which resulted in greater compound degradation and lower antioxidant activity than in high temperature variant SDMD50.