## 3 Results and Discussion
### Taste Profile of Seed Powders Using an \"Electronic Tongue\"  
An electronic tongue known as an artificial tongue or taste sensor is an analytical instrument used to classify flavors in liquid food samples. Its principle of operation mimics the human sense of taste. The analysis uses the sensors responsible for each primary flavor, which, when placed in the sample, can detect a given flavor and compare it quantitatively with the flavor present in the sample [38]. In the electronic instrument, the interpretation of the taste quality perception is achieved by the e-tongue's statistical software, which interprets the sensor data into taste patterns. This is due to practical considerations, preparing dilution series of tastants is highly time-consuming--as is the determination of thresholds; therefore, based on the combination of all the sensors' results, the unique fingerprint of each tasted powder was generated.  
Figure 1 shows the differences in the intensity of the basic tastes: salty (CTS), sweet (ANS), sour (AHS), umami (NMS) and bitter (SCS) in the seed powders tested, as determined by electronic tongue. Considering the results obtained, it can be observed that the samples differed more from fruit to fruit than from drying method to drying method. The mango seed powders, those obtained by both convective and sublimation drying, were characterized by a higher intensity of sour (AHS), salty (CTS) and sweet (ANS) flavors in the rambutan powders, which in turn showed more intense bitter (SCS) and umami (NMS) flavors. The aforementioned relationships are also presented in Figure 2a-c, which shows the graphs formed on the plane formed by the different flavors: salty (CTS), sour (AHS) and umami (NMS). Considering the obtained results distributed on the plane formed by the sour (AHS) and salty (CTS) flavors (Figure 2a), it can be observed that the mango seeds were characterized by a higher intensity of these tastes, while on the plane formed by umami (NMS) and salty (CTS) taste (Figure 2b), or umami (NMS) and sour (AHS) taste (Figure 2c), rambutan seeds showed a higher intensity of umami (NMS) taste and a lower salty (CTS) or sour (AHS) taste in comparison to mango seeds. Considering the method of obtaining the seeds (sublimation vs. convection drying), the greatest taste discrepancies were obtained for rambutan seeds in terms of salty taste (CTS). No data were found in the available literature regarding the taste profile of powders obtained by different drying methods from exotic fruit seeds, such as mango and rambutan. Considering the literature data on the applicability of the electronic tongue, it was concluded that it could be useful  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Powders** & **Water Activity [a\({}_{w}\)]** & **WHC** & **WSI [\%]** & **pH** \\ \hline MSCD & 0.21 b \(\pm\) 0.002 & 1.57 a \(\pm\) 0.13 & 12.6 a \(\pm\) 0.08 & 6.18 \(\pm\) 0.02 \\ MSFD & 0.03 a \(\pm\) 0.001 & 1.59 b \(\pm\) 0.11 & 17.4 b \(\pm\) 0.06 & 6.21 \(\pm\) 0.02 \\ RSCD & 0.23 b \(\pm\) 0.002 & 1.29 b \(\pm\) 0.16 & 9.5 A \(\pm\) 0.12 & 7.02 \(\pm\) 0.01 \\ RSFD & 0.03 A \(\pm\) 0.001 & 1.22 A \(\pm\) 0.13 & 11.2 b \(\pm\) 0.10 & 7.06 \(\pm\) 0.02 \\ \hline \hline \end{tabular}  
* Means in columns with different letters within the same type of powder (a)b for mango seed powder, \({}^{\mathrm{A,B}}\) for rambutan seed powder) differ significantly (\(p<0.05\)); MSCD—conventionally dried mango seed powder; MSFD—freeze-dried mango seed powder; RSCD—conventionally dried rambutan seed powder; RSFD—freeze-dried rambutan seed powder.  
\end{table}
Table 1: Physicochemical properties of mango and rambutan seed powders dried by different methods.