## 3 Results and Discussion
### Multi-Layer Perceptron vs. Spray Drying  
Spray drying is the most commonly used method of drying liquid products due to the possibility of obtaining a powder in one short operation and the relatively short time during contact between the product and the heating agent. The spray drying method started to be developed at the end of the XIX century. The method started to be used on a large scale in the second decade of the XX century to obtain, among other things, milk  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**No. ** & **Application** & **Descriptors** & \begin{tabular}{c} **Air** \\ **Temp** \\ **[\({}^{\circ}\)C]** \\ \end{tabular}  & \begin{tabular}{c} **Air** \\ **Velocities** \\ **[m.s\({}^{-1}\)]** \\ \end{tabular}  & \ \begin{tabular}{c} **Fruit and** \\ **Vegetable** \\ \end{tabular}  & *** Structure** & **R\({}^{2}\)** & **Year** & **Ref. ** \\ \hline \multirow{4}{*}{1.} & \begin{tabular}{c} various temperatures \\ (classification of \\ texture parameters) \\ \end{tabular}  & GLCM texture feature & \(60,70,80\) & \(1.0\) & sweet potato & \(6\)-\(11\)-\(4\) & \(0.55\) & \(2022\) & [60] \\ \cline{2-10}  & \multirow{2}{*}{moisture ratio} & drying time, initial & \multirow{2}{*}{50–\(60\)} & \multirow{2}{*}{0.5} & \multirow{2}{*}{orange Valencia} & \multirow{2}{*}{5-\(3\)-\(1\)} & \multirow{2}{*}{0.9811} & \multirow{2}{*}{2022} & \multirow{2}{*}{[64]} \\  & volume, area difference, & moisture content, final & & & & & & & \\ \hline \multirow{4}{*}{3.} & \multirow{4}{*}{drying rate} & effective moisture & \multirow{4}{*}{50–\(60\)} & \multirow{2}{*}{0.5} & \multirow{2}{*}{orange Valencia} & \multirow{2}{*}{3-\(2\)-\(1\)} & \multirow{2}{*}{0.8618} & \multirow{2}{*}{2022} & \multirow{2}{*}{[64]} \\  & & diffusivity, moisture & & & & & & & \\ \cline{1-1}  & content, final volume & & & & & & & & \\ \hline \multirow{4}{*}{4.} & predict the moisture & air temperature, airflow & \multirow{4}{*}{5, 50, 55,} & \multirow{2}{*}{0.75, 1.0,} & \multirow{2}{*}{apples} & \multirow{2}{*}{3-\(10\)–\(10\)–\(1\)} & \multirow{2}{*}{0.99} & \multirow{2}{*}{2020} & \multirow{2}{*}{[65]} \\  & concentration changes & velocity, drying time & & & & & & & \\ \cline{1-1}  & during drying of apple & & & & & & & & \\ \hline \multirow{4}{*}{5.} & moisture content & temperature, flow & \multirow{4}{*}{40, 50, 60} & \multirow{2}{*}{1.0, 2.0,} & \multirow{2}{*}{quinces} & \multirow{2}{*}{3-\(90\)-\(90\)-\(1\)} & \multirow{2}{*}{0.99} & \multirow{2}{*}{2020} & \multirow{2}{*}{[68]} \\  & evolution (predictions) & velocity, time & & & & & & & \\ \hline \multirow{4}{*}{6.} & classification (ripe and & frequency (Hz) and the & \multirow{2}{*}{60} & \multirow{2}{*}{1} & \multirow{2}{*}{strawberry} & \multirow{2}{*}{2-\(14\)-\(1\)} & \multirow{2}{*}{0.980} & \multirow{2}{*}{2020} & \multirow{2}{*}{[71]} \\  & over-ripe fruits) & level of luminosity (dB) & & & & & & & \\ \hline \multirow{4}{*}{7.} & prediction of color & \multirow{4}{*}{50, 70} & \multirow{4}{*}{-} & \multirow{4}{*}{-} & \multirow{4}{*}{-} & \multirow{4}{*}{0.887} & \multirow{4}{*}{2020} & \multirow{4}{*}{[73]} \\  & parameters, vitamin C & & & & & & & & \\ concentrations and & \(\beta\)-carotene & & & & & & & & \\ concentrations & & & & & & & & & \\ \hline \multirow{4}{*}{8.} & physical and chemical & \multirow{4}{*}{type of root vegetables, \(\powder [80]. Next, it was applied to dry eggs and coffee [81]. Currently, this method is applied when drying food articles in the form of solutions and suspensions of milk [82], honey [83,84], juices and fruit concentrates, for example, strawberry [85], chokeberry [86], rhubarb [87] or raspberry concentrates [88,89, 23]. In the process of spray drying, the direct parameters that affect the product obtained are the drying parameters that are properly selected, including drying air inlet temperature, drying air flow rate, liquid stream feed rate and spray air pressure.