## 3 Results
### Physicochemical Properties of Powders  
#### 3.5.1 Particle Morphology and Size  
Particles of obtained buckwheat honey powders (Figure 2) were mostly spherical, with the exception of SDMD50, which had more irregular particles that were bigger in size (the highest \(D_{50}\)). Spray drying at higher drying temperatures, as in the case of SDMD50, leads to early structure formation of rigid particles, which results in greater \(D_{50}\). [PERSON] et al. (2020) stated that an increase in particle size is usually observed when the stickiness related to low \(T_{g}\), increases [17]. This implies that variant SDMD50 was more difficult to spray dry than other variants, which was confirmed previously by the lowest \(R_{p}\) and can be observed as well on cumulated particle size distribution curves (Figure 3). Moreover, particles were usually scattered, except for DASDMD75, in which clusters were formed. The cluster-type morphology is also characteristic of materials difficult to spray dry due to a stickiness; thus the variant DASDMD75, with high honey content, can be classified as problematic as well based on morphology analysis. Moreover, difficulties in spray drying of this variant can also be seen on cumulated particle size distribution curves (Figure 3). However, this was not confirmed by \(R_{p}\), presumably due to the increased size of created \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & **SDMD50** & **DASDMD50** & **DASDMD75** & **SDMP50** & **DASDMP50** & **DASDMP75** \\ \hline \(Q\) [RW] & \(3.4\pm 0.0\) 1  & \(7.3\pm 0.0\) 2  & \(7.2\pm 0.8\) 3  & \(3.9\pm 0.4\)4  & \(6.6\pm 0.0\) 5  & \(6.9\pm 0.5\)6  \\ \(E_{s}\) [M]/kg & \(24.8\pm 0.1\)4  & \(41.8\pm 0.9\) 5  & \(40.6\pm 2.9\) 6  & \(22.9\pm 2.6\) 7  & \(37.6\pm 1.0\) 3  & \(39.5\pm 2.6\) 7  \\ \(\eta\) [Y] & \(9.6\pm 0.0\) 5  & \(5.7\pm 0.0\) 4  & \(10.5\pm 1.2\)  & \(6.4\pm 0.0\) 4  & \(6.1\pm 0.0\) 0  \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Rate of energy consumption (\(Q\)), specific energy consumption (\(E_{s}\)) and energy efficiency (\(\eta\)) of conventional spray drying (SD) and dehumidified-air-assisted spray drying (DASD) of buckwheat honey solutions containing 50 and 75% honey solids and maltodextrin (MD) or milk powder (MP) as carriers. clusters that can be observed in high \(D_{50}\) (Table 3), which promoted the effective powder separation in a cyclone. Smaller bridges between particles were also present in SDMP50 and DASDMP75 variants, with SDMP50 having the lowest \(R_{p}\). However, DASDMP75 had the highest \(R_{p}\) even though the morphology indicated that it could have been a variant that caused problems during spray drying, as particles were visibly more piled up together as a result of the high honey content. This lends support to previous findings in the literature by [PERSON] et al. (2017), who noted the same results when carrier content in honey spray drying was decreased from 50 to 25% ([PERSON] et al., 2017). As discussed before, \(R_{p}\) is a factor that can also be dependent on other properties like \(D_{ap}\) due to the impact on cyclone efficiency. DASDMD50 and DASDMP50 had small, scattered particles, indicating easy drying at low temperature and with a high content of carrier. Variants where MP was used as a carrier (DASDMP50, DASDMP75) in comparison to variants with the same carrier content where MD was applied (DASDMD50, DASDMD75) were more spherical, smooth, uniform, less conglomerated and had particles that were less scattered. These results validate the usefulness of MP as a carrier with regard to particle morphology and prove its skin-forming properties. These findings are in good agreement with [PERSON] and [PERSON] (2016), who traditionally spray dried honey with a protein-based carrier (WPC) and observed particles with a smooth surface that were less susceptible to cracking ([PERSON] et al., 2017). [PERSON] et al.