## 3 Results
### Powder Recovery  
Spray drying performed at laboratory or pilot scale is considered to be successful when \(R_{p}\) is higher than 50% [13]. Results noted in this research varied from 62.9 \(\pm\) 2.1 to 96.8 \(\pm\) 5.2%, indicating successful spray drying of all of the variants (Figure 1). Moreover, in the case of DASD variants, values exceeded 75%. Several studies, i.e., [PERSON] and [PERSON] (2015), [PERSON] et al. (2013), [PERSON] et al. (2015), [PERSON] et al. (2020) and [PERSON] et al. (2019), have been conducted on honey spray drying and process performance [12,17,20,30,31]. The \(R_{p}\) of buckwheat honey spray drying was presented only by [PERSON] et al. (2015), and the authors observed results ranging from 67.8 \(\pm\) 2.1% to 75.8 \(\pm\) 4.9% [12]. However, the authors spray dried honey conventionally with different carriers and their content than presented in this paper (sodium caseinate and/or Arabic gum as a carrier, honey solids to carrier solids 50:50).  
The results obtained in this paper have confirmed the previous observations made by [PERSON] et al. (2019) and [PERSON] et al. (2020): that the application of dehumidified  
Figure 1: Powder recovery (\(R_{p}\)) after 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. a–c The differences between mean values with the same letter in rows are statistically insignificant (\(p<\) 0.05).  
air enables the production of honey powders with significantly higher \(R_{p}\) than presented in previous literature for SD [17, 20]. [PERSON] et al. (2005) explained in their work that the greater difference between material's \(T_{g}\) and product's temperature (\(T_{p}\)) leads to greater stickiness and consequently to lower \(R_{p}\)[32]. As dehumidified air enables lower drying temperature, the degree of stickiness is smaller because of the smaller \(T_{g}\) and \(T_{p}\) difference, which was noted in this research as manifested in high \(R_{p}\) in DASD variants.  
It is crucial to underline that the highest \(R_{p}\) values (87% and 97%) were obtained at the lowest carrier content, in variants DASDMD75 and DASDMP75, respectively. This non-evident relationship can be explained in relation to cyclone efficiency. \(D_{ap}\) and \(D_{50}\) are parameters that influence particle separation from drying air in a cyclone [33, 34]. Powder particles of bigger \(D_{ap}\) and \(D_{50}\) result in more effective particle separation, thus manifesting in greater \(R_{p}\). This presumably explains the high \(R_{p}\) of variants DASDMD75 and DASDMP75, which had high \(D_{50}\) and \(D_{ap}\), respectively (Table 3). On the contrary, SDMD50, which had the highest \(D_{50}\), did not show high \(R_{p}\), due to increased stickiness at high temperature SD.  
Moreover, obtained results indicate the significance of the carrier used, which can be observed in the variants with the lowest carrier content. The \(R_{p}\) of buckwheat honey powder spray dried with MP as a carrier was significantly higher than with MD, though only for sample DASD75 was the difference statistically significant. As presented before by [PERSON] et al. (2009), [PERSON] et al. (2013) and [PERSON] et al. (2014), obtained results confirm that carriers containing proteins with film-forming ability prevent inner particles' sticking and particles sticking to the walls of the drying chamber, which in turn increases \(R_{p}\)[31, 35, 36]. Despite the fact that lactose characterizes with significantly lower \(T_{g}\) (101 \({}^{\circ}\)C) than MD (100-243 \({}^{\circ}\)C, depending on dextrose equivalent), due to the additional combination of film-forming properties of milk proteins, variants with MP as carrier resulted in higher \(R_{p}\)[13].